Looks like no one else wants to venture a reply here. Guess I'll give it a stab.
Yes, his PF call was typical Titan fish-like. Then he had position on you.
As far as the turn: Well, you were kind of at a decision point that would be hard to argue one way or the other. On one hand, the board was paired and Mr.Fish could have the 3rd (K3 even). On the other, you were somewhat committed and had decent pot odds
with your pair.
The river check was not bad. He might have folded anyway.
Just feel lucky you didn't have AA and got rooked.