1) Keeping in mind that this ultimately was a prank, I think it's fair to point out that 9 times out of 10 there isn't more to the story when it comes to these situations. So calling for that tends to read as dismissive at best, and worst a clear signal to search for the thing that will allow people to craft a "See!? He was no angel!" defense.
2) I'm not the all-seeing-mod who knows the story behind every ban. But banning for skepticism tends to only happen when you're skeptical in a way that dismisses concern for actual racism/sexism/homophobia/what-have-you that actually occurs.
1) It was just pranks bro!
2) We don't ban for skepticism, we add some other bullshit to it too!
example of era acceptable skepticism:
"while extremely unlikely, it is possible that these men were actually guilty of stealing from this chipotle, but I must stress this is EXTREMELY unlikely (but still possible (but seriously unlikely)). And even if they did, this woman shouldn't have wielded her power over a black man in this way. And also this would be an extremely unfortunate turn of events, because alt-right assholes would use this example for years to come and would be hedging a narrative/rhetorical loss for the good guys (which is why even though possible I don't think it's likely plz don't ban)."