I'm going to have to raise the BS flag here too. AA completely controls the WOs, so if they wanted someone fired that bad they could just instruct the WO to fire them. Even off probation there's always a legitimate reason to fire someone. It's not hard. Spend a little time as a union rep. We screw stuff up every day that nobody would notice unless they were looking, and for certain people they're looking.

Unless you can give me actual numbers of people who flowed to AA and were fired due to background issues, this is nothing but another urban legend. Even if it did happen, like Rick said, the offense probably happened while they were at the WO and they hid it and AA found it. Duh.