Well, I guess he could be making the checkraise on the flop with a flush draw/straight draw or even air as well as a set here. He checked the turn, and maybe CR'ed the flop to get a free card on the turn OOP. The river bet looks a little like a busted flush draw, and I could imagine him with a six there and some kind of flush draw like
.
More likely scenario: he checkraised you there with TP(or even a limped AA or KK), shut down on the turn after you called, but after you checked the turn, he went ahead and tried to rep the straight with a bluff. As least it looks like a bet that doesn't want to get called...either way, this guy plays badly postflop. I'm still not sure if you have the winning hand or not, but I wouldn't have been too wild about calling that river.
I guess he could have done a CR on the flop with any pair, putting you on AK because, well, everyone and their mother puts their opponent on AK...makes it easier to donk off your money when you convince yourself you are ahead.