Penance for the 84 Bears-Raiders game.
On the Bears side McMahon got a kidney laceration that game, out for the rest of the season.
Raiders' QB1 (Jim Plunkett) was injured so they started their QB2 (Marc Wilson) who gets concussed very early on, he's taken out and they put in their QB3 (David Humm) who gets strip sacked almost immediately.
So then Wilson gets put back in, he breaks his thumb, so now Humm's back in again. Humm gets sacked so hard his front teeth fly out. Next snap his knees get annihilated and that ended his career. Raiders' QB4 is literally their punter and he refuses to go in because he doesn't want any part of that shit.
The Bears sacrificed many QBs on their way to a ring and now they are being repaid in kind.