“Discernment”
That is the nub of the issue—when to believe testimony is real and when to dismiss it as lies or false.
The best way to get that is to do lots of homework—lots of focus on details—a full understanding of the history.
Most of the Freepers howling “squirrel” have just not done the work.
The “textbook” on the topic is Richard Dolan’s classic two volume history btw:
https://www.amazon.com/UFOs-National-Security-State-Chronology/dp/1571743170
https://www.amazon.com/UFOs-National-Security-State-1973-1991/dp/0967799511
Somebody hocking a book still doesn’t make it science.
I read Chariots of the Gods as a teenager. It’s largely been debunked. But he made a pretty penny off his books back then.