Hey guys, first post ever so have patience.

I was playing the big 11 yesterday, went fairly well, had a very pre-flop nitty supernova elite player 3 places to the left of me.
As he folded most bbs in early blind levels i decided to attempt a steal with J3s and he 3-bet me. I tanked for a little while and called, the flop came 894 with two diamonds, i figured i could take one call to his c-bet as i flopped the flush-draw and backdoor straight draw. The turn was a complete blank and he checked quite fast to me, I thought for a little while, (max 15 sec) and then raised half pot, he then moved in rather quickly.

Now obviously, I wish i would just have checked and hit my flush there, but my question is, seeing as this is a good player with very nice opr stats and a supernova elite status, is he sometimes bluffing in this spot seeing as my raise on the turn looks so goddamn weak? He probably figures I'm aware of his status, and his nitty image so I figured he could be 3-betting rather light, therefore the call pre, the c-bet is standard, as is the call with the draw, but on the turn, when he check-raises all in, does that always mean the nuts to you guys or could you ever call there if you had the J9s and had the one pair with a flushdraw?

Sorry for things being a bit messy, look forward to your thoughts.
Thanks!