I'm generally not posting in here anymore, but regarding the 'crash' theory, there are also stories/rumors about us finding in-tact craft without the 'crash' part. Even David Grusch has said the US has "intact and partially intact craft".
Lue Elizondo has also said publicly that UAP's can be tracked with a specific electromagentic frequency, and others have claimed and written about
UAPs being 'bricked' during high-altitude nuclear detonations.
And in terms of witness testimony, I always found this one from Lance Corporal Jonathan Weygandt to be fairly intriguing because of his delivery in terms of words, pace, and body language that suggests somewhat accurate recall.