Blatent bluff, or easy laydown?

[pr0crastin8r]

Villain kinda loose, maybe hyper-aggressive at first glance... not a very good read though.

Party Poker $50 No-Limit Hold'em (6 max, 4 handed) converter

Button ($117.8)
SB ($69.6)
Hero ($47.9)
UTG ($44.65)

Preflop: Hero is BB with T[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $0.25.
UTG calls $0.50, Button calls $0.50, SB (poster) completes, Hero checks.

Flop: ($2) K[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, <font color="#CC3333">Hero bets $2</font>, UTG folds, Button calls $2, SB folds.

Turn: ($6) T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $5</font>, Button calls $5.

River: ($16) 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">Button bets $40</font>, Hero ????.

Final Pot: $56

My gut told me to call, and that nobody would make a bet that big that wanted to be called... but my brain got the better of me. Which should I have listened to? How often would you say these LHAGs are abusing the scare card?