I honestly think it's incredibly important for tools like this to be publicly available for this exact reason.
If they're not and they're hoarded by tech companies or intelligence agencies then we'll just have a lopsided system where people aren't aware of how capable such technologies are, what their limitations are, how to analyze them to spot issues, etc.
Imagine if only nationstates knew about these sorts of technologies and used them for war or if only certain elites in tech had access to them and used them to implicate competitors in crimes? The technology is out there now - at this point, public knowledge is our best defense - people always question if a contentious image is photoshopped, we want that same level of questioning to happen for videos.
In terms of this being used as an excuse to get someone out a criminal charge, it might make us take a better look at the chain of custody on video evidence but I don't think it would invalidate it completely.
There are corrupt governments/police that would be able to use this tech to create fake evidence against people so its really important that everyone knows this is possible.
Maybe, to some extend, it will invalidate video proofs at some point.
This might seem nice against ever growing CCTV, but probably state security cameras will be "trustworthy" and all media evidence gathered by private persons will be dismissed...
Or false incrimination, false flag operations and so on. You can start a war with a video. That might change to some degree as trust in video decreases, but what trust will take its place?
We could already, and we probably did, fake video to start wars. The tech just make it easy for everybody, but state actors have been manipulating pictures for a long time.
The first consequence of this tech is that we'll have to stop trusting video evidence. What you describe is a use case that will only be valid for a short period of time while society adjust.
What GP is describing is the long term consequence of not being able to trust video evidence. Now even if you film someone red handed, they can deny it.
Another dire consequence is that the entire archive of all videos filmed since the beginning are now tainted by doubt. Any past politician speech, any past horror caught on film, etc. can now be said to have been crafted recently.
Stalin used doctoring 70 years ago with pitiful tech, and it worked. Today even basic photoshop skills can do much better, and it doesn't matter if it's called out by the righ people, it will have done damages. Some people still confuse The Onion articles with real ones after all.
If they're not and they're hoarded by tech companies or intelligence agencies then we'll just have a lopsided system where people aren't aware of how capable such technologies are, what their limitations are, how to analyze them to spot issues, etc.
Imagine if only nationstates knew about these sorts of technologies and used them for war or if only certain elites in tech had access to them and used them to implicate competitors in crimes? The technology is out there now - at this point, public knowledge is our best defense - people always question if a contentious image is photoshopped, we want that same level of questioning to happen for videos.
In terms of this being used as an excuse to get someone out a criminal charge, it might make us take a better look at the chain of custody on video evidence but I don't think it would invalidate it completely.