Playing A5s from the Big Blind

[Sandwich]

This hand caused a ruckus at the online table last night. Was everyone justified in berating my play, or was it just sour grapes? This was early in the sit and go, and I think it put people on tilt and/or colored people's perceptions of my play for the entire rest of the tourney -- they wouldn't let this one hand go. I'd like to hear what people here think (especially my raise on the turn w/ a flush draw)....

Early in a $30+3 Party Poker Limit Hold 'Em Sit and Go Tourney (10 handed)

Hero is in the BB and is dealt 5/images/graemlins/club.gif A/images/graemlins/club.gif

Preflop:
UTG folds, UTG+1 folds, UTG+2 calls, MP1 folds, MP2 calls, MP3 calls, CO folds, Button folds, SB completes, Hero checks.

Flop: (5 SB, t75) K/images/graemlins/club.gif, 9/images/graemlins/club.gif, 2/images/graemlins/diamond.gif <font color="blue">(5 players)</font>
SB checks, Hero checks, UTG+2 checks, MP2 bets, MP3 calls, SB folds, Hero calls, UTG+2 folds.

Turn: (4 BB, t120) 6/images/graemlins/diamond.gif <font color="blue">(3 players)</font>
Hero checks, MP2 bets, MP3 calls, Hero raises, MP2 calls, MP3 calls.

River: (10 BB, t300) Q/images/graemlins/club.gif <font color="blue">(3 players)</font>
Hero checks, MP2 bets, MP3 folds, Hero raises, MP2 calls.

MP2 shows K/images/graemlins/spade.gif 9/images/graemlins/heart.gif and MHIG.

[Tosh]

Not keen on the turn check raise. Can't call it a value raise with only 2 others in the pot and you aren't winning this pot uncontested.