EPT Dublin, how do u react to the mistake of the guy

[Cuts]

This hand happened at EPT Dublin, just before the dinner break of the day 2. I was chipleader day 1, and was deep during day 2 until I lost a huge pot against villain, who is Simon Munoz a spanish guy sponsored by unibet.
I knew nothing of him before he came to my table, he's on my direct right but still very tough to play (he can float flop/turn to bluff river, stuff like that isnt common in tournaments).
After the huge pot lost against him I have about 80k at 1k/2k/500, and he has more than 250k.

Here is the hand:

He raises in MP to 6k, I repop in the cutoff to 18k with JJ, back to him, he calls.

flop is K94 one club.
He checks and I check behind, I'd do that with AK and he knows that, I'm just trying to control a little bit the size of the pot knowing he wont fire the turn often here.

turn is 9 club.
He asks me how much I got behind, I say 65k and he bets 32.5k
So here I put him on air or draw, I have no idea why he would bet that much with a 9 or a king, so I'm thinking about moving in when I see the floor director doing something. I remove the ipod and I'm told that villain made a string bet, this is not allowed so the bet is 2.5k.
To be honest I just called without thinking here, still i don't think it's a mistake.

River is an ace, not a club.
Villain bets 35k.


I'll post my thinking process later and my decision.