BB folds 50% from a steal, but my steal backfires.

[Wada]

Victim is 19/6/.4 and attempts to steal 23% but folds BB to steal 50%! He is the BB and I am the button.

2/4 Hold'em (6 handed)

Preflop: Hero is Button with 8[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/spade.gif[/img].
UTG folds, MP folds, CO folds, <font color="#CC3333">Hero raises</font>, SB folds, BB calls.

Flop: (4.50 SB) 6[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets</font>, BB calls.

Turn: (3.25 BB) K[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, Hero checks.

River: (3.25 BB) 8[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets</font>, Hero ?????????