[Spoilers] I thought Mitch at the beginning seemed to be acting in a way that didn't make sense.
If one tries to tell AJ that what he did was wrong and try to seek atonement from the group, Mitch's response is something along the lines of
"See? How can we trust these people!?"
While I definitely understand the hostility Mitch displays, I don't think he's expressing it in a way that normal people would. What I expect would be something like "You're being ridiculous if you think we'll ever forgive you," or something like that. Not "They're being apologetic. This is clearly an example of how untrustworthy they are! How could we ever trust them?"