SNG heads up - str8 draw on paired flop

[nicky g]

6-handed $10+1 SNG on UB, now we're heads up . We both have about even chips, with the blinds at 30-60. In the SB I get 7 [img]/images/graemlins/diamond.gif[/img]8 [img]/images/graemlins/diamond.gif[/img] and flat call, which I think was a mistake as he was folding a lot to raises. He checks. Flop is 996. He checks, I bet the pot - 120. He check-raises another 120. I'm pretty sure he has a 9 but feel I am priced into calling here. Turn is a 5. I bet out 500. He raises 1000, I go all-in. he has 94, river is another six giving him a house to beat my straight. I fume.
Was this a just bad beat or should I have got out earlier on? Fearing full houses heads-up seems like looking for monsters under the bed, and I think he played it badly by letting me draw out, but with the blinds relatively small should I have waited for another spot to commit my chips when I am fairly sure that he has outs to a full, though he probably doesn't have one yet?