What if his stats are something in the order of 30/15 preflop, and his postflop stats resemble those of someone trying to play well?
If he raises many hands preflop, AK, AA and KK don't really fit the pattern. Weak aces might, though, and that's the problem holding in this scenario.
The reason this hand stood out as interesting is because of the implications of his bet. With a read like the one I supplied, he's doing one of three things:
1. He's bluffing
2. He's betting a hand like KQ to see if I'll fold (because he sure isn't happy about stacking off with it)
3. He's betting out with a big hand (i.e. 77) hoping that I'll raise.
In case 1, well... I dunno. It's a risky board to bet a second barrel into a guy who raised preflop.
In case 2, he'll - presumably - check/fold the turn. A decent player isn't going to call a bet on the turn with second pair on an ace-high board.
In case 3, I will have a decent chunk of implied odds. Clearly, though, I will fold to a turn checkraise if he goes for it since checking behind for a free river is something that defeats the purpose of floating.
Oh, and I agree that it's close. But I find that I learn so much from the close decisions.