The preflop play is the most interesting thing about this hand.
Why would anyone flat a $250 all-in 4-bet with pocket aces rather than 5-bet?
1) You do it for deception. A 5-bet after all that action screams AA or KK if the 5-bet player is tight.
2) you do it trying to trick/trap the other big stacks left to act. This play does increase the risk for a player with pocket aces, but the low SPR acts as a buffer to the risk.
a) Maybe Hugo the LAG will get frisky with the top end of his likely wide open range. Maybe Hugo the LAG will stack off on the flop with top pair or an overpair.
b) We do not know Hero's table image. It could be the trap is laid for Hero, expecting he might go all-in trying to isolate.
The reason why a thinking tight player doesn't set mine with a smaller pair is that he isn't getting good enough odds. It costs him $250 to try and set mine - roughly one chance in eight to flop a set. But what can he win? The pot is at best going to be $1,000 and the effective stacks are 1,350 (Hugo), 1,050 (hero), 1,350 (Peter). So Peter needs to flop a set AND get other of the other players to stack off AND not get beaten by a better hand even with a flopped set AND not get 5-bet all in preflop, AND if Peter gets all of elements of the parley to work out he makes barely better than the 7-1 odds he had to flop a set.
Playing deep stacked poker is complicated. It gets worse when you have a 125BB "short stack" mixed in with people playing 650BB+ deep. If he actually had held a top 1% hand, Peter would have been facing a hard [ though enviable ] spot pre-flop. Jamming is the safest play, it gets Peter heads up with 40 + 120 + 250 + 250 in the pot and an estimated 80% equity - so risking $250 and expecting to win something like $525 ----> that gives a $275 profit for one play, damn good for a $1/$2 game. But if Peter can somehow get a sidepot with one of the other deep stacked players, he stands to make something like four times more than the safe play. IF it works out as planned, because we know the tricky play is not as safe as a shove.
How about Hero's preflop line? I can respect the isolation raise to $120 trying to trap a possibly drunk LAG playing a deep stack. It isn't for the faint of heart, but that kind of play can pay off handsomely.
But what are we to make of Hero's decision to flat the 4-bet all in? On the surface, the pot odds are excellent but the implied odds are tricky. Hero has to flop a pair or flush draw to continue with hand post flop. Hero is getting trapped if he flops as ace vs someone with AK or if he flops a queen vs a player with an over pair. I am inclined to fold hero's AQs if I respect Hero's read of "Good player, not drinking, TAG" because I can't see any hand in his range that is worse than Hero's AQs.