This appears to be well sourced, going back to the '40s. There are references to zero point energy, diseases from contact between individuals and Non-Human entities, magnetic field drives, antigravity, craft being shot down, etc.
If I’m not mistaken, I believe this is what Knapp gave Rep. Burchett.
How embarrassing would it be if you were an alien in a space craft to be able to be shot down by human weapons.
That would be like a monkey with a rock taking me down when I have an assault rifle.