Hold accountable? Thanks for the laugh.

After everything we've been through so far I trust a random guy on social media far more than a government infested with maniacs who have no problem with killing presidents.
I never said government authority. I said "forensic stamp of authenticity."
Any private individual or company with the technical tools and skills to authenticate digital media can publish the what, how and why of whether the media is unaltered.
Simple example: a watermark. Digital watermarks on video are used to protect digital video. It's added during recording by the equipment. Many media outlets require these watermarks on equipment they issue to videographers to prevent them from selling footage they shot for the company using their cameras. Since it's added at time of creation, it can be verified with software. Superimposed watermarks added after shooting the video doesn't pass the test.
if you have a video with metadata showing the file was created 5 days after the event, that's a good indication it's fake as well. Most video today is created digitally on phones or cameras. There's no need to render it like you did for analog recordings. So, even if the file shows a timestamp later than the event because it was copied to a storage device, the metadata would still show when it was created. If it's altered, the metadata would normally change, too, unless someone tried to go into the file and alter the metadata. if they didn't use the altered video to fool people, the metadata is probably intact. So, when others share it as real, it's simple to show it's not.
Many other ways to tell if the media was altered. It all depends on how much effort the creator puts into concealing that it's fake. None of the methods i know of can evade every forensic tool.