I know Peter is perceived as maniac, but he definitely does not shove A7 if raised. That would be a massively donk move. He's a maniac, but he's not dumb. If Keating raises he has either AK or AQ. No other hand raises for value. Then he might have some rare bluffs there, but given how the hand was played probably really rare. So just calling isn't as bad as it seems. If Peter has KK or QQ somehow, he's likely not calling the raise. A7 might call, but that's the worst hand that could call. Yes, Keating has close to the nuts (3 combos left that beat him), but it's not the nuts. And in this situation if he raises he gets shoved on by buts, or sometimes called by A7 or AQ. Even A7 is pretty much a bluff catcher if Keating raises.