HOTD: Turned flush then river pairs

.01/.02 Omaha with .59 in front of me and everyone else at the table has me covered. I limp with AJ98 in MP and there are four of to the flop which comes KQ3 two hearts giving me a nutter gutter to broadway and the nut flush draw, 11 clean outs plus maybe Qh if that doesn't boat someone up. Checks to me and I decide to just try to peel off a free one. Button makes a half-hearted stab of .04 into a pot of .13 in the middle. BB calls, MP1 calls and I call to put .24 in the middle now. Turn brings 5h which gives me the nuts. Checks to me and I want to try to milk this a bit since I suspect someone else might be on a heart draw as well since it is one of the obvious draws on the flop and the stab got three callers so I put out a half pot bet as meekly as I could in case anyone wants to come over the top but the BB just calls and nobody else follows us to the river. River brings another 5 and BB checks to me. I've said it before that people see themselves in other players and sure enough I just check behind in case the guy was going to check-raise me which I immediately recognized as a mistake. Does he really have a boat here? Why would he check when I am clearly repping a flush and not a set? He loses all value by letting me check behind when I will certainly call something if I have a flush and will check behind if I have nothing so there is nothing to be gained by checking his boat. And how did he get there? He check/called a bet from the button on the flop with a set on a draw heavy board? Really? Maybe I guess but you'd figure most people would run right through the opened door. Did he have just a pair then made two pair on the turn? Then why is he calling the flop? Pocket fives would definitely check call the turn but how can anyone just check quads? If he indeed has anything he will call a modest value bet and if he comes over the top well all in, well then he can have it even though he butchered the hand. Though the value bet may have only been a couple BBs every little bit helps. If he paid off even three cents then that would negate the effect of rake on that hand to me. Turns out he had K3 for top and bottom on the flop then called off a half pot sized bet on a four outer when all the river did was counterfeit him. A sub-optimal play but also a reminder to always try to squeeze out as much extra value from a hand as possible.