Stars 20/180 TP vs Turn Min-Raise...What the...???

[erc007]

PokerStars No-Limit Hold'em Tourney, Big Blind is t400 (8 handed) Hand History converter Courtesy of PokerZion.com


Button is bad...but has been getting very lucky. He's not aggro at all, esp post flop. He didn't raise small river bets twice, once with the nut flush and the other time with the nut str8 (boards were paired both times, but given the previous action, FH was very unlikely.) I've never seen a line like this...min-raise pre, lead for min on the flop, call a raise...then min-raise again on the turn? What could he have here...this is not the type of player to semi-bluff a draw.
Hero (t12200)
UTG (t10715)
UTG+1 (t9545)
MP1 (t4995)
MP2 (t11717)
CO (t5769)
Button (t23524)
SB (t7671)

Preflop: Hero is BB with 8[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/spade.gif[/img].
5 folds</font>, Button raises to t800</font>, 1 fold</font>, Hero calls t400.

Flop: (t2000) A[[img]/images/graemlins/heart.gif[/img]], K[[img]/images/graemlins/club.gif[/img]], 2[[img]/images/graemlins/heart.gif[/img]] (2 players)</font>
Hero checks, Button bets t400</font>, Hero raises to t1500</font>, Button calls t1100.

Turn: (t5000) 4[[img]/images/graemlins/diamond.gif[/img]] (2 players)</font>
Hero bets t3000</font>, Button raises to t6000</font>, Hero...???