crazy Pot Limit HE game, AQ hand

[absinthe]

Right, so a buddy of mine brings me to this weekly game. Blinds are 50c/$1, but it's not table stakes. No all-ins - you either fold, or put up an IOU. You can bet up to the pot, even if you don't have the chips. In other words, the chips are pretty much pointless. No restrictions, if you can't handle the bet, you fold.

The players are pretty good at reading people, but don't know a damn thing about the cards. They're the "any two" type.

So it's 10-handed or so, my buddy gets AQo in EP, puts in $3, and gets 2 callers (an unusually low number). $11.50 in the pot at this point.

Flop comes K Q 5 (suits not particularly important). My buddy bets $6, gets one caller ($23.50 in the pot now).

Turn: Another king, now K (K Q 5), rainbow. My buddy bets pot. The opponent deliberates for a while, and calls. Now $70.50 in the pot.

River: A blank (let's say it was a 2, nothing's really a blank in this game, but hey). Board: 2 (K K Q 5). My buddy checks, and the opponent says, "Pot." My buddy thinks about his next rent check for a while, and folds.

Thoughts on my buddy's play? Given his play up til then, how should he have handled the river?

Anyway, after it's over, the opponent shows AQo as well. I know this is pretty much depends on the read of the players, but would love to hear any input.