Well... I'm sure we've all watched, or at least heard of the alien autopsy. You were presented with 2 hours of so called facts, and expert approved testimony that made it hard to refute the validity of the show.
The film itself, claimed to be from 1947. And the serial number film, as verified by Kodak, can be from the year 1947, or 1967. But film experts said the film quality is not that of 1967. The behaviour of the camera is that what was used by the military then. The table, the trays, the clock, the devices and utensils match that of what was used in 1947. Even if this was all replicated to it's full authenticity, to create an alien with the correct skin attributes and characteristics is an incredible accomplishment for the uncut time duration it was shown. So even if it could be replicated, the cost would be astronomical, yet the film was not produced by ILM or any cutting edge film production agency. It would also be 100% impossible to make an alien like that, fake, in 1947.
Reefer, after watching the tape concluded that it's fake because they chopped up an alien in 23 minutes. If it were a real alien, you would think they would chart out the inards, and be ultra careful. Plus, they would probably have a great number of cameras to record every single detail. Then Fox came out with another one about the aircraft, and that basically nuked any validity alien autopsy may have had. One thing is for sure, it was gross.