herein2020

Yes, it looks like they came to the same conclusion that I did....its not feasible for video. Also their implementation of encryption for the sake of speed is very weak. The 64 LFSR encryption method can be reversed in less than an hour with a fast enough modern computer, even they admitted it wasn't very good and had to be downgraded from the typical 256bit standard due to IO speeds and that was in 2014.
Your comparison of 5200RPM drives is mixing apples and oranges, the drive read/write speed is not where you will see the most penalty, typically the encryption/decryption is done in the CPU which is where you could get up to a 30% hit when reading/writing to the encrypted drives. Modern CPUs tend to have way more power than most users need so you wouldn't notice the hit to the CPU unless you did a before and after benchmark and modern CPUs are designed to perform cryptographic functions efficiently. The problem of course as I mentioned earlier, is that cameras do not have all of these spare CPU cycles laying around or onboard TPM chips. In the Magic Lantern example the camera's CPU would be needed to encrypt every byte of data in real time which is where the performance penalty and unreliability would kick in. 
A camera cannot afford to lose 30% of its CPU and encounter up to 20%+ more storage latency when recording video or shooting bursts of images; the buffer would never have a chance to clear.
The true hardware solutions like the USB-C drive I sent you manage to skip this penalty because you are technically writing to a storage space after passing through a dedicated encryption chip whose only purpose is to encrypt the data; data which can then only be read after the proper pin has been input into that dedicated encryption chip. Even though this may still incur a small penalty in IO, you manage to get enough remaining IO to conform to the USB-C standard which means it will have enough remaining IO bandwidth to meet the USB-C data transfer standards.
Quick Google Search
http://cherrybyte.blogspot.com/2012/11/quick-comparison-of-disk-performance.html
https://www.phoronix.com/scan.php?page=article&item=2019-linux-encrypt&num=2
https://www.isumsoft.com/computer/how-much-does-bitlocker-impacts-on-hard-disk-io-performance.html

I agree 100% with you. I have the C200 and due to the file sizes have never shot raw for a paying job.  For the types of jobs that I do, as long as you WB and expose properly the files sizes of raw don't justify the benefits. YouTubers seems to think raw is the holy grail that will instantly turn their cat videos into cinematic blockbusters.
With that being said, most people when discussing raw seem to think its only benefit is its ability to have more latitude in color grading. I had a long discussion with Blackmagic Design and the real benefit of raw is the fact that it is designed for editing. For this reason alone I wish the C200 and C70 had compressed raw options. I have no problems with the image quality out of the C200, C300, and C70, but I cringe thinking about trying to edit those files after adding titles, color grades, Fusion effects, and transitions.

I have the GH5 with the XLR adapter and a MixPre6 as well as a C200. I think the XLR adapter or XLR straight into the C200 is great for a single mic or a mic and a backup mic, but I learned the hard way just a few days ago that if you have multiple speakers the Mix-Pre is way better. It was a pain to manually audio duck in Davinci Resolve the two speakers that I had; the stereo mix out of the MixPre for 4 speakers was less work than manually mixing two speakers from the onboard audio.
 
For the C70 I really don't consider the mini XLR a big deal, as you mentioned it is not as bad as mini HDMI. One thing I wouldn't do though is leave the adapters plugged in, I always feel like things sticking out of a camera port will weaken the circuit board over time as they get wiggled and moved in your bag. I'd just load up on about 6 adapters, two go in my emergency kit in my car (along with memory cards, random power cables, etc), two stay in the bag with the camera at all times (since they are so small) and two go in my dedicated audio case where I keep all of my cables, the MixPre, etc. 
 
Also, for my particular use case, this camera would primarily be a gimbal camera, audio would not be that important to me.

That would work but wouldn't be a great option, in addition to not being able to review the footage the camera would not be able to verify the integrity of the file after dumping the buffer unless it also signed each file then checked the signature prior to clearing the buffer.  Any way you look at it, the encryption process would incur overhead; processing, heat, HW, development, etc. and include compromises (complexity, possible lost data, additional costs, etc) for a very small target client base. 
Also, if you really are in a scenario where the government seizes your camera; if they can't read the data and you are physically unable to provide the decryption key on the spot they will now have an excuse to search the rest of your gear or they will simply destroy the storage medium.
Once again phones have the advantage here, they already have network connectivity, they already have data at rest encryption options, they can already livestream events as they happen, etc. Trying to reverse engineer all of that and put it into a camera then trying to market and sell that camera simply isn't something any for profit camera maker would do.
 
All of the encrypted SD cards that I have seen require a full OS or some way of loading their decryption/encryption application onto the device; something that would be impossible to do with a camera. There may be one that I am unaware of (entirely possible), but I haven't seen a simple SD card you can just plug into a camera and have it encrypt everything that is written to it. I believe they all need an app, and you need to enter the proper authentication information into the app prior to using writable space on the card. I have seen USB drives that have physical PIN pad buttons which is how you enter the volume password like this one: https://www.amazon.com/Apricorn-Validated-256-bit-Encryption-ASK3-120GB/dp/B00W2EN8CE/ref=sr_1_1?dchild=1&qid=1601314672&refinements=p_n_feature_keywords_browse-bin%3A6813186011&s=pc&sr=1-1 but for that to work the camera has to support writing to a USB drive or SSD drive.
The FlashAir SD card looks like the best option, but it looks like it would be complicated to setup and get to work reliably. Just turning on and off the camera would require the offloading device to reliably reconnect to the wifi, the app to automatically grab the files as it detects them, then move those files to a cloud backup solution (and we are talking large JPGs here).  It's been my experience that getting that many different technologies to work together reliably and repeatedly is uncommon.

My wish is that all of this so called H.264 and H.265 hardware accelerated encoding actually worked. I'm sure it helps but it never seems to be enough to make actual editing smooth and I always end up making proxies anyway.
With that being said I have pre-ordered the C70. I figure its better to be on the list and cancel then to wish I was on the list. I have been thinking more and more about cancelling though, although this is my dream gimbal camera the more I think about the type of jobs that I do the more uncertain I am that I would be willing to use a camera this costly to do them. Weddings, events, music videos, and corporate work simply do not need a $6KUSD camera on a gimbal. The R6 is what I truly need and the camera that is in the right price bracket for my work but we all know how that turned out.
 

That does sound like the best solution then, at least for images; ironically the cell phone still sounds like the best solution for video.  Fortunately in my line of work the most hostile environment I may be in is the father of the bride dislikes who the bride is marrying.

I agree 100% with you. I have the C200 and due to the file sizes have never shot raw for a paying job.  For the types of jobs that I do, as long as you WB and expose properly the files sizes of raw don't justify the benefits. YouTubers seems to think raw is the holy grail that will instantly turn their cat videos into cinematic blockbusters.
With that being said, most people when discussing raw seem to think its only benefit is its ability to have more latitude in color grading. I had a long discussion with Blackmagic Design and the real benefit of raw is the fact that it is designed for editing. For this reason alone I wish the C200 and C70 had compressed raw options. I have no problems with the image quality out of the C200, C300, and C70, but I cringe thinking about trying to edit those files after adding titles, color grades, Fusion effects, and transitions.

That would work but wouldn't be a great option, in addition to not being able to review the footage the camera would not be able to verify the integrity of the file after dumping the buffer unless it also signed each file then checked the signature prior to clearing the buffer.  Any way you look at it, the encryption process would incur overhead; processing, heat, HW, development, etc. and include compromises (complexity, possible lost data, additional costs, etc) for a very small target client base. 
Also, if you really are in a scenario where the government seizes your camera; if they can't read the data and you are physically unable to provide the decryption key on the spot they will now have an excuse to search the rest of your gear or they will simply destroy the storage medium.
Once again phones have the advantage here, they already have network connectivity, they already have data at rest encryption options, they can already livestream events as they happen, etc. Trying to reverse engineer all of that and put it into a camera then trying to market and sell that camera simply isn't something any for profit camera maker would do.
 
All of the encrypted SD cards that I have seen require a full OS or some way of loading their decryption/encryption application onto the device; something that would be impossible to do with a camera. There may be one that I am unaware of (entirely possible), but I haven't seen a simple SD card you can just plug into a camera and have it encrypt everything that is written to it. I believe they all need an app, and you need to enter the proper authentication information into the app prior to using writable space on the card. I have seen USB drives that have physical PIN pad buttons which is how you enter the volume password like this one: https://www.amazon.com/Apricorn-Validated-256-bit-Encryption-ASK3-120GB/dp/B00W2EN8CE/ref=sr_1_1?dchild=1&qid=1601314672&refinements=p_n_feature_keywords_browse-bin%3A6813186011&s=pc&sr=1-1 but for that to work the camera has to support writing to a USB drive or SSD drive.
The FlashAir SD card looks like the best option, but it looks like it would be complicated to setup and get to work reliably. Just turning on and off the camera would require the offloading device to reliably reconnect to the wifi, the app to automatically grab the files as it detects them, then move those files to a cloud backup solution (and we are talking large JPGs here).  It's been my experience that getting that many different technologies to work together reliably and repeatedly is uncommon.

I have never even looked through my GH5's EVF, I always use the flip screen. It is way steadier to tuck your elbows and hold the camera with a 90 degree bend in your elbows close to your body than to try to use the EVF.  From there I can do pans, tilts, simulate slides, etc. all handheld.  If you mean using the EVF for shoulder work then yea they want you to buy a bigger model for that, but for handheld I hate the EVF, I completely disabled it in my GH5 to save the battery life.
 
 
I love the idea of the S5 but after buying that and a few L mount lenses it would cost me more than the C70. When I travel I actually just use my 5DIV, and the Mavic Pro, since my travel work is not paid and the 5DIV has really good 1080P which is enough for me to use as b-roll clips later on for things like music videos, nature etc.  If I am traveling on a paid assignment then usually it is just video and I take the GH5.  If I'm traveling for a paid hybrid gig then I lug the 5DIV with the 24-105 and the GH5 with a few lenses...so yea this camera doesn't help at all in that scenario.
I'm thinking even local hybrid shoots though, I would still need to lug around the C70 and the 5DIV.  Many times I just need photos and some b-roll video clips...I don't trust either the R5 or R6 to do this right now. For long form stuff I still have the C200.

I'm waiting for the GH6 as well. I do think an L-mount GH6 would be a bad idea, they already have that with the S5, and the reason I am not interested in that is specifically because it would mean I have to get L mount lenses to have a native system.  If the GH6 has 4K 120FPS and some form of in body compressed raw options that would be good enough for me. Not having to buy new lenses or buy into a new system is the main thing I care about.
I don't think Panasonic will ever get PDAF, there's rumors Sony simply won't license it to them, how true that is I have no idea but I have to believe that if Panasonic had it available to them they would have implemented it by now. With that being said, my C200 has DPAF and I still almost always shoot with MF, I just don't trust AF for critical shots, so if the GH6 has no useable AF that's not a deal breaker for me.
The Canon C50/C70 looks pretty fascinating but I'm still at least a year away from getting over my disappointment in the R5 and R6. I already have a C200 and a GH5, I don't need another body that can't take pictures as well as video, what I need is an R6 that actually lives up to its marketing materials.

The codecs are pretty annoying...strong for Canon but below avg for the competition. Editing those types of files nearly always need to be transcoded first. I do think it would do great for corporate work and it would be nice to use a single camera for both gimbal work as well as interview type work. Right now I use my C200 for interviews and tripod work and the GH5 for gimbal work and b-roll. For lower budget clients I could use this camera for both.  If I need RAW I can use the C200 or rent another body.
The URSA 12K looks great but it is over twice as much and the gimbal for it will cost more than this whole camera, not really considered a run and gun camera due to the extra rigging required, it will need proper lighting and rigging to get the most out of it, and the storage needs are astronomical. It definitely has its place but the URSA and C70 simply aren't meant for the same target audience. I like to stick with bodies that can shoot 90% of my work and for that last 10% I can always rent the gear needed for the project.
One thing I can't tell is if APS-C lenses will work with the C70. I know they have the speedbooster, but no one has said if the speed booster will only work with FF or will it work with APS-C lenses as well. My favorite C200 lens is the 18-35 Sigma APS-C lens.

We're talking two unreleased cameras, but the internal NDs, mini XLRs, higher framerate 4K, and superior autofocus would make the Canon a clear winner over the S5 for docs.
Unless you literally have to have two cameras for $4000, in which case there's no point comparing them.

I'm waiting for the GH6 as well. I do think an L-mount GH6 would be a bad idea, they already have that with the S5, and the reason I am not interested in that is specifically because it would mean I have to get L mount lenses to have a native system.  If the GH6 has 4K 120FPS and some form of in body compressed raw options that would be good enough for me. Not having to buy new lenses or buy into a new system is the main thing I care about.
I don't think Panasonic will ever get PDAF, there's rumors Sony simply won't license it to them, how true that is I have no idea but I have to believe that if Panasonic had it available to them they would have implemented it by now. With that being said, my C200 has DPAF and I still almost always shoot with MF, I just don't trust AF for critical shots, so if the GH6 has no useable AF that's not a deal breaker for me.
The Canon C50/C70 looks pretty fascinating but I'm still at least a year away from getting over my disappointment in the R5 and R6. I already have a C200 and a GH5, I don't need another body that can't take pictures as well as video, what I need is an R6 that actually lives up to its marketing materials.

Yes Resolve is incredible, but it can be pretty hard to find some of its features. I think the key to my color grading workflow is I don't add the adjustment layer until I have a base grade for all of the clips, that way I don't accidentally end up with it selected. It's pretty annoying that DR does not provide an easier way to do this, and I accidentally start working on the wrong layer all the time if I have already added say a logo or watermark at a higher layer. I now try to color grade before adding text/titles/callouts etc. but if a client wants changes after seeing the project that's where things get time consuming.
 
I learned the memories trick from the following video, and out of all the different ways to copy a grade to another clip I liked it the Memories trick the best, if the clips are side by side I just hit the = key but it usually doesn't work out that way. For speed purposes I just put everything into one node unless I'm doing something complex like power windows, selective color, green screen work, etc. I used to do multiple nodes and all of that but it takes too much time; create a base grade, throw a finishing LUT into an adjustment layer....done.
I literally did not leave Premier Pro until DR added the adjustment layer feature. It is a huge time saver.
 
 
 

My entire process is set up for speed, so it may not yield the quality that you are looking for but my workflow is as follows; some of the steps may help you speed up your workflow....
1 - Import all of the footage from the memory cards to the PC into a folder called RAW clips (sub folders separate the clips by camera)
2 - During the import separate them by camera using the sub folders  (I typically can have up to 4 cameras)
3 - I have a second folder called selected clips
4 - I open the RAW clips folder in one window and the selected clips folder in a second window
5 - I preview each clip in VLC then drag it to the selected clips folder if I will use it. Any clip that looks totally unusable (false start, etc. I drag to a discards folder).
6 - From the selected clips folder I drag it into DR
7 - I build out the timeline do all of the edits etc until the project is done. I dump all of the cameras on a single layer and only add layers for text, multi-cam scenarios, overlays, special effects, etc. I don't bother labeling the cameras, naming the clips etc (unless I am going to add it to my stock footage library). Every min I spend on a project is $$ lost is the way I treat projects.
8 - I move to the Color tab and when I encounter the first camera I apply a grade that brings it to the Rec709 standard based on the WFM. Once the grade is complete (LUTS, manual adjustments etc) I save it to Color memory slot 1 > Color > Memories > Save Memory A (or just press  Alt 1). Each time I encounter that camera I press Ctrl 1 to apply that camera's grade. For the rest of the cameras I repeat the process. By the 4th camera I have base grades for all of them saved. 
9 - After pressing Ctrl + camera number to paste  the grade on the next clip from that camera, I make small adjustments in case it is the same camera but a different scene (i.e. indoors vs outdoors etc).
10 - After all of the base grades are done I go back to the edit tab and add an adjustment layer over all of the video clips but under any titles/text/logos etc. 
11 - I go back to the Color tab and apply a finishing LUT to the adjustment layer.
12 - Color grade done
With my process my entire color grade for a typical 2-5min project with 4 cameras and 100 clips takes less than 10min.  I have optimized my workflow to minimize the throwaway clips in my NLE, maximize my editing speed, and with the added benefit that if I start running out of storage space in my archives I know I can go back and delete unused footage from the Discards folder without affecting the finished project. Also for speed, my entire folder structure for photography and video is set up as a templates in a read only folder so I just copy that folder structure each time into a new project folder when I start a project. I hate spending 1 additional unnecessary second on a project if I can help it.
I tried DR's Use Remote Grades feature but for me it was confusing and annoying to work with if a single clip had multiple exposure changes (say walking from outdoors to indoors or the sun went behind the clouds) so I like the memories slot approach better.  I also tried the apply grade by camera approach using bins but there is no single camera base grade that will cover every scenario so I found it faster to build a base grade for that particular project for each camera by hand or via a LUT with manual adjustments. I have also had multi-day projects where the next day was a completely different venue and there is no way I would want to use the same grade from the previous day even though it was the same camera.
My process I'm sure would fall apart for really large projects but for me where the typical project never exceeds 4 cameras or 100 clips it works great.

I know I'm just one customer and Canon obviously couldn't care less about my business but I know I had planned on replacing the GH5 with the R6, replacing the 5DIV with the R5 and eventually replacing the C200 with an RF mount equivalent along with RF mount lenses over the next 2-3yrs...so I'd say they lost around $60K of my business so far. As it stands now, if a GH6 comes out I'll use it as a b-cam to my C200, keep the GH5 and use it as a c-cam.

I know I'm just one customer and Canon obviously couldn't care less about my business but I know I had planned on replacing the GH5 with the R6, replacing the 5DIV with the R5 and eventually replacing the C200 with an RF mount equivalent along with RF mount lenses over the next 2-3yrs...so I'd say they lost around $60K of my business so far. As it stands now, if a GH6 comes out I'll use it as a b-cam to my C200, keep the GH5 and use it as a c-cam.

I call them flying lawnmowers and take extreme care to not fly over people.

$43K USD....and here I thought the Inspire 2 was expensive. It still doesn't look that integrated to me, they just took two existing products and did the work needed to make them talk together. A truly integrated solution is the Inspire, Phantom, and Mavic lines. I used to own an Inspire but it was overkill for the work I do, the huge case, poor battery life, poor wind performance (no one mentions that an Inspire flying in a cross wind is less stable than a P4 in the same crosswind), and setup time weren't worth the increase in image quality that none of my clients were willing to pay for.

I for one will never go back to shooting anything less than 4K and typically nothing lower than 4K60FPS.  I already have over 120TB of storage, my projects drive is 4TB, my cache drive is 1TB, 14 core CPU, RTX 2080TI video card, USB3 media readers, 1TB SD cards, and I  always generate optimized media for every clip to have smooth playback after color grading and Fusion effects are added. I rely heavily on recomposing shots, stabilizing in post, straightening the horizon (drone footage), and couldn't imagine losing all of those capabilities.  I shoot 4K60FPS because I never know when I might need to slow something down later as part of a speed ramp or to get additional gimbal stability. Interviews of course are shot at 4K30FPS.
 
I typically then deliver in 1080P although lately I have been editing on a 1080P timeline then upscaling to 1440P for a YouTube delivery. For my website's demo reels I need the highest quality so I have Vimeo Basic which is free but has a very low storage limit so I put about 4 or 5 videos there until I reached the storage limit so that customers see a higher quality video than YouTube would allow. I also tried hosting a few MP4s on my website but that's just too unreliable; maximum quality but it's a pain to write the code to detect the different viewports and deliver the proper format based on the user's devices.
 
I get what you are saying about the additional overhead, but all of it is paid for by my clients. I charge for each project based on the number of hours it will take for me to shoot, edit, and deliver that project and my service proposals are based on processing, editing, and rendering 4K footage. Clients hire me based on my past work, they expect to get the same level of quality that they saw from other projects, the only way I can do that is by shooting in 4K or higher and delivering in 1080P or upscaled 2K. I have never shot a single frame of video in my GH5, C200, GoPro, or drones at 1080P. If you plan for 4K, build your workflow around 4K, and charge your clients for 4K it's really no different than 1080P.  If you are not making a living from video work and just posting personal projects on YouTube then 4K might not make sense.

Yes that makes sense, that's the same reason why I only use OEM batteries...why try to save $20 on a battery in a $4K camera? It makes no sense when people get cheap parts for expensive gear; or the endless iPhone chargers with the cheap cables that can fry the iPhone port, the chargers die within weeks, and there's been cases where cars and houses have caught on fire, just to save a few $$ vs the OEM gear. 
All of my power related accessories (charger, v-mount adapter plate, v-mount battery) is bebob and so far its been great: http://bebob.de/en/v-mount.html the battery is so expensive I still only have one, but that one can power the camera and monitor for around 6hrs nonstop.
I did do a lot of research before I ordered the accessories for the C200 and only got the top of the line gear for it especially in the power and cabling departments; the only thing I don't trust is the dummy battery cable, I couldn't find one that wasn't a cheap mod from China.
I've been in the IT/electronics field for around 20yrs myself, I still remember using ESD bags and grounding straps to insert circuit cards and oscopes to check waveforms for signal noise and circuit issues...the days before electronics became disposable. That was so long ago I couldn't even turn on an oscope let alone know what I'm looking at these days.

exactly the same here on electronics and IT equipment (almost 30 years now paying the mortgage with that stuff).  As they push more voltage out the SDI and HDMI ports, there is a growing chance of voltage going an unintended path.  But seriously  with good quality cables, components, and process, you are fine.  You have $20k in your C200 setup, so I'm sure you take operating it seriously.  I think those that are going to see a problem don't put much thought into plugging and unplugging, and use the cheapest parts that can "do the job".  It's a little harder for this to happen with HDMI, but easier with SDI 6G and 12G.  In high speed SDI 12G, I saw my first Galvanic video and ground path isolator.  This little device is around $400 (supposedly you can still get 12G speed, but not so sure though), thing was so small, was easy to leave attached to the cable.  I just saw an article describing a Lentequip Safetap, but at around $150 and some DIY work,  seems a bit much, but probably smart if you rent your gear out (which are the folks I have been trying to help with this issue).  For those of us that own and operate our own gear, we are going to take care of that investment.  
I think the reason you and I didn't see this with electronics and IT equipment, is because that equipment has true grounded wiring (on a camera rig it's self contained), is AC based, and better circuit isolation.  This potential issue is different.  You have 2 pieces of gear tapping into the same capacity source AND enter in a 3rd piece that connects between them, that is using more and more electricity lately (as SGI and HDMI get faster), yet still no where near the current levels of the 2 main pieces.  It would be like having a pc sized UPS powering 2 servers (with all of them only connected to each other with no true earth bound ground).  Now connect them together with 10Gbps or higher ethernet cable.  You now have a similar scenario.  Though, it is possible that circuitry in servers does a better job at isolating.  

That's good to know, I've worked with electronics and IT equipment for many years and the first rule of thumb was to always remove power before connecting or disconnecting anything, so when I got my adapter plate I made sure it had a power button. The part I wasn't sure about was if there were any high capacity capacitors anywhere in the circuit that could still cause problems after the power was removed. I used to mod cars with custom audio systems and those audio caps could fry anything they touched weeks after the power was removed.
Of course now my concern is someone accidentally pulling out the HDMI cable while everything is powered on, I'm paranoid enough that I may still use a dedicated battery for my monitor. I've got about $20K into my C200 so I'm a little more paranoid than if it were something smaller.

Canon for me has more problems than the obvious (fake overheating). I really like the GH5's XLR adapter, dual slot video recording, and no video recording time limits.  The R6 will still cutoff at 29min even if it did not overheat, it will not record video to both cards at the same time (only images), and I'd have to give up XLR audio without some clunky additional workaround like an external XLR recorder. On the other hand it has Canon's colors, will hopefully get CLOG3 which will perfectly match with the C200, and will take fantastic images.
The S5 will have nearly all the same problems as the GH5 (no AF, no CLOG3, no Canon colors, not something I would want to use for photography) but at a much higher price point with the marginal benefit of maybe a little more DR and maybe better highlight rolloff.
It is like everyone keeps saying, there is no perfect hybrid; at this point it is starting to almost seem deliberate; but I just don't see what any of these companies have to gain by coming so close then failing so miserably in the areas that matter the most.
I'm with you, I am definitely sitting this year out and hoping next year will be a better one. If next year is like this year, then I guess I'll sit that one out as well....everything I have works just good enough that I don' t have to make compromises to get into my next camera body; I'm already making compromises and at least those have already been paid for (and paid for themselves), the rest of this year I am going to focus on improving my Davinci Resolve editing skills.

That is a nice feature.  If there is no voltage flowing, then the circuit in question is dead.
Most systems don't have that switch option. 
I had posted an easy to remember "you always start and end with power" in your case you are doing that by disabling the power source.
Also, remember this was more a possibility on SDI 6G/12G because the BNC cable could have a proceeding positive that touched before the ground completing the circuit through SGI 😮   This has been reported to happen with HDMI solutions, particularly with the faster HDMI 2.0 and 2.1 (that new 2.1 spec is crazy fast at 48 Gbps).  Most likely the gold connections were a tad higher for positive and/or neg had oxidation or lint or something, allowing postive to touch first.  In that scenario if you have a powered circuit to both your camera and recorder from the same power source, your hdmi in that scenario can complete the circuit.  Many times it can happen quick enough that the higher currents in the battery circuit don't spend enough time in hdmi or sdi to do damage, but in other cases it can fry the hdmi or sdi circuit (they just weren't meant for those levels of currents).
All that being said, if you use good quality cables, V Mount plates, C Mount Battery, etc. you are less likely to experience an issue.  But if you just follow a good workflow when operating your camera, you can avoid this issue all together.  Always start and end with power.  Get your power circuits in place and then add input/output.  Before shutting down remove all input/output, then disconnect power.  The important thing is to keep that power circuit in place to keep the voltage and current in the right places and using the correct grounds.