To me, the river bet of $5, the same bet as on the turn, says that he doesn't like that 4 on the river but still wants to put some money out there to not look weak when a possible set presents itself. If he thought he had the hand won, he'd have probably lead out with a larger, but still attractive 1/2pot bet or so.

You've got the best hand here. I'd put him on a flush draw on the flop. Maybe AT or KT perhaps. Caught the T along the way which is probably why he still threw the river bet out there. I'd re-raise him to about $15 and hope to get a call.