looking back over the HH, I think in this situation the turn check looks like exactly what it was, a turned nut flush. I hadnt noticed how small that flop bet was, but .75 into a 2.50 pot looks like a drawing hand, not a hand that is made and could be scared of another heart, ie. TP, set, etc. then the check when the fourth flush card comes just reeks of a nut flush. meaning the only hand that can call your river push is a straight flush. now, if you had bet a regular amount on the river and he pushed over, i would say you quickly call, but the river bet seems like a really bad play.