Calculating odds

I just had a pretty disgusting experience:

Party Poker
No Limit Holdem Tournament
Blinds: t30/t60
9 players

Pre-flop: (9 players) Hero is Button with K♠ A♥

UTG calls t60 (pot was t90), 3 fold, Villain calls t60 (pot was t150), CO folds, Hero raises to t240, 2 fold, UTG calls t180 (pot was t450), Villain calls t180 (pot was t630).

Flop: T♠ Q♠ 3♠ (t810, 3 players)
UTG checks, Villain bets t810, Hero raises all-in t2180, UTG folds, Villain calls all-in t690.

Uncalled bets: t680 returned to Hero.

Turn: 8♥

River: 4♥

Results:
Final pot: t3810

Villain shows [ 8s, Ad ]a pair of Eights.
Hero shows [ Ks, Ah ]high card Ace.
Hero wins 680 chips from side pot #1 with high card, Ace.
Villain wins 3,810 chips from the main pot with a pair of Eights.


My opponent was just bluffing of course and got lucky (if he was playing to make his flush, he should have bet less, because now he was not getting the right odds). However, after playing this hand I realized that I had calculated the odds incorrectly. At the crucial point the pot is 1620 and I need to call 810. However, if I do call, he only has 690 left which makes him pot committed. So I should have treated his bet as an all-in call, since his money will definitely go into the pot after the turn (assuming he is not an idiot, which is perhaps a bad assumption, but he will have the opportunity to bet 690 into a pot of 2430 which are of course great odds, even if he needs to make the flush on the river (he cannot know that his flush would be useless)).

So his bet was actually 1500, making the pot 2310, and now I need to pay 1500, giving me odds of only 40%. However, in the current hand this mistake does not make a difference, since I am actually 60% favorite to improve, so there was no bet that he could make that would make it wrong for me to call.

Conclusion? I played correctly, but am not happy about the result. That's poker I guess!