$109 Rebuy on Stars-Heads up Hand

[Vagos]

Just won Stars $109 rebuy but lost this critical pot heads up. The guy was auto betting a lot of turns when it was checked to him twice, it happened a couple times 3 handed and a couple times heads up. My hand is somewhat weak but consider the blinds, I didn't think it was bad to play top pair and OESD this way, even with 3 hearts on board. All thoughts appreciated.

PokerStars No-Limit Hold'em Tourney, Big Blind is t20000 (2 handed) converter

Button (t158008)
Hero (t235992)

Preflop: Hero is BB with T[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/diamond.gif[/img].
Button calls t10000, Hero checks.

Flop: (t31000) 7[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, Button checks.

Turn: (t31000) T[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">Button bets t40000</font>, <font color="#CC3333">Hero raises to t214992</font>, Button calls t97008 (All-In).

River: (t383000) 2[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players, 1 all-in)</font>

Final Pot: t383000