Along with the physical events that followed, yes, it did. You can't prove they didn't see what they saw. In other cases of government culpability (e.g., TWA 800), the exclusion of eyewitness accounts is a key sign of a cover up.

I haven't seen such videos, and I am more susceptible to the expectation that they are frauds created by "truther" fanatics. Conspiracy fanatics are not above such hoaxes. The "xxxx-trails" and "Fxxx-Earthers" are in that category. But if you can provide a link, I am willing to view what you deem to be so irrefutable.