funny call from big blind

[oneeye13]

from a $20 pokerstars tourney, sb is loose, sometimes aggressive after the flop.

PokerStars No-Limit Hold'em Tourney, Big Blind is t150 (9 handed) converter

Hero (t2075)
UTG (t8474)
UTG+1 (t6205)
MP1 (t6418)
MP2 (t8705)
MP3 (t5528)
CO (t2775)
Button (t1335)
SB (t5085)

Preflop: Hero is BB with J[img]/images/graemlins/heart.gif[/img], 3[img]/images/graemlins/spade.gif[/img].
<font color="#666666">7 folds</font>, SB completes, Hero checks.

Flop: (t300) K[img]/images/graemlins/diamond.gif[/img], T[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, Hero checks.

Turn: (t300) 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, Hero checks.

River: (t300) A[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets t300</font>, Hero calls t300.

Final Pot: t900

Results in white below: <font color="#FFFFFF">
SB has 3c 7h (one pair, tens).
Hero has Jh 3s (one pair, tens).
Outcome: Hero wins t900. </font>