What'd you put him on when playing the hand? If he's playing a set I ran a small range of hands involving the top set. You can easily be far behind if he has top set and a low draw better than yours (or if he's suited with any low draw). Still assuming the set, you're only going to be even if he has a worse low draw and isn't suited or has no low draw at all.

If you put him on something other than a set... you're probably ahead but it's still near coin flip territory.