I do - I think the videos and pictures that protestors smuggle out become less powerful if the state can dismiss them as fake and while most of us will remain skeptical of authority the more easy it is to fake something the more people you can convince of your falsehood.

I don't think the lack of a durable chain of custody really provides any protection - that protection needs to come from a strong legal system and social contract to protect whistleblowers. If you're thinking of, as an example, an Iranian smuggling out protest footage, they're already taking an extreme risk and have a state using numerous tools to try and track them down - but the lack of a durable chain gives a wide area of authorities to cast doubt on the truth.

I think your question is interesting to ponder and I think there are arguments in both directions - but my mind keeps coming back to the tank man photo being smuggled out of China and how much more difficult it would be in the modern world for a single image to carry such weight.