Depend just how much credit i give him, which will be hard for you to tell over 40 hands i guess.
If i think he's just a wannabe lag, calling 3bets with lots of stuff preflop without really knowing why and automatically making moves with any kind of overcards+gs hands on flops like this one that don't hit your range very well, i might just decide to call his raise and call the shove on any turn with the Ts. I would have had to see him do some stupid stuff first tho, anything to make me think he's overdoing his lag style.
If i think he's a decent lag, the flat of the 3bet oop will worry me a lot more, and here is why. Lag players will screw around on these garbage flops quite often, and everyone knows that. Which means their opponents automatically put them on some kind of draw and decide to make a stand with their overpairs, even tho they are often up against something like overcards+FD that have massive equity against them, or just plain crushed by the occasional set. What they do to exploit that is flatting KK+ preflop, even tho they are out of position, to keep in all the stuff that would fold to a 4bet like AQ/TT-JJ possibly QQ, so that when people make a stand with their JJ on rag flops, the lags end up being way ahead anyway. Especially these days where everyone seem to agree that the flat of a 3bet in position is often AA planning to shove the flop over the c-bet pretending to be a draw, a flat out of position by somebody who knows what he is doing should ring even more alarm bells once he c/r the flop.
So when a good lag raises that flop, committing himself with his flushdraws in the process, you have to worry not only that you can be up against something like 66 (~dead) or KsQs (flipping), but also KK+(~dead). I don't think the "but this is a weak fold, i have an overpair in a 3bet pot 
argument is quite enough to justify going broke in that spot with one of the shittiest overpair against those guys at these stakes.
Nowhere near an exact science of course, especially after only 40 hands, just some things to think about i guess. I would tend to think that a 30/27, raising almost every hand he has played so far and who apparently bought in for 100b, is not just some random donk, and err on the safe side.
