[kgu1]

This actually looks like a pure bluff imo. First let's rule out the types of hands he can have.

Sets are out of the question. I think BvB, he would've 3 bet you with 99 or 88 and even if he didn't, villain would have raised you on flop with a set since the board is quite fluid.

A flush is almost not possible here either. If he did have a flush draw on the flop, he also most likely had two overs to go with it, something like KTs, or QJs, etc. and would have reraised you to build the pot.
Now... I don't think villain is even semi-bluffing here with Ax of clubs here. His second card would have to be at least a Jack of clubs or higher, and BvB... I think he would have reraised you pre-flop with AJ-AK. He's never reraising you on that turn with a T of clubs or lower, because you could easily either already have the flush or have the redraw to a higher one. The only possible hand that semi-bluffs this is Kc9 here, but I think imo that is the only legit hand that semi-bluffs. His line then, just looks like complete air or he's playing a random two pair very strong. Either way, you have him crushed and I'd ship it in here.

Now... all this information could be very inaccurate depending on the player villain is, but just going by the "average" 1/2 player, this is what I think is going on.