98o defence. Turn mistake? Check-fold 2 bottom 2 on river?

[Allday Everyday]

5 handed 5/10 Online.

Vilain's 5 handed stats are: 23/18/1.9. Attempts to steal: 30. I have him as a good player who doesn't make many mistakes.

Preflop: Hero has 9 [img]/images/graemlins/spade.gif[/img] 8 [img]/images/graemlins/club.gif[/img] in BB.
Fold, fold, Button raises, fold, Hero calls.

Flop: K [img]/images/graemlins/club.gif[/img], 9 [img]/images/graemlins/heart.gif[/img], 8 [img]/images/graemlins/heart.gif[/img].
Hero checks, Button bets, Hero raises, Button calls.

Turn: J [img]/images/graemlins/spade.gif[/img].
Hero bets, Button raises, Hero calls.

River: Q [img]/images/graemlins/heart.gif[/img].
Hero checks, Button bets...