[Quix]

Considering the miles of credible files in the last 6 decades . . .

I don’t know of a better word than crazy . . .

but perhaps . . .

ill-informed,
clueless,
willfully blind,
poor-at-sifting—masses-of-complex-info,
paradigmly challenged,
paranoidly traumatized at the thought,
arrogant to the max,
rigidly narrow and obsessive in squeezing ‘reality’ into very tiny pseudo-tidy little boxes,
. . .
. . .

could substitute for “crazy” in a pinch.

[Travis T. OJustice]

Credible, only to the insanely gullible.

[AlexW]

“Considering the miles of credible files in the last 6 decades . . .”

Considering the miles of not very credible credible files in the last 6 decades, there is still no proof that ET has ever visited Earth ! There, I fixed it.