No, he claims to have heard from others. He hasn't seen anything. Pure hearsay.
Which is simply not good enough, astronaut or not. Astronauts are as fallible as the rest of us.
You yourself mentioned that he had seen evidence, how else could it be interpreted?
No. No scientist would ever do something like that.
You seem to think that astronauts are infallible. Guess what, they are not. They are as nutty as the rest of us. Like Lisa Novak that drove 900 miles wearing a diaper to hit her rival on the head. Edgar Mitchell has a belief, fair enough, but that is all that he has and he has explicitly stated that that is all he has.