Dude,
Let it go. No hiring system is perfect and even the best hiring and screening practices, yes even "proven ones" are not 100%.
There will always be good folks rejected and some "strange rangers" that make it through. Just look at NASA - not many jobs screen so selectively from such a highly qualified pool..............and yet they hired a wack job that drove halfway across the country wearing a diaper to assault a sexual competitor. You really cant make this stuff any wackier.
As for "saving" your Captain - good job, sounds like our hiring department made the right choice with you.
I doubt you will ever make a mistake in your career but if you do, hopefully your fellow crew-member will have your back just as you had your Captains back.
I for one will wait until I am retired on the porch with a scotch in hand before I start criticizing my fellow crew-members.
Scoop