That 1/2 pot bet on the river could be a "please call" bet or a horse shit under-bet because he think you hit the flush by calling all 3 streets (or both for that matter).

What good is raising? I don't see how I can justify dumping half my stack into a hand by calling down only to find out I've just been taken to value town. Of course we're getting good odds to call, but are we that positive we're ahead? So did he get taken to value town? Split pot, what? Hell if I know. The OP posted no post-flop reads whatsoever. At NL FR I'm around 12/8 but I'm practically a maniac post flop. So telling us villain is 11/6 means nothing to me except he's opening with something half-way decent.