[CopTHIS]

This doesn't even look close to me tbh, easy fold. He may be turning a hand into a bluff sometimes I guess but I see this so often from this type of player with an OK flush +. I def don't see it as nuts or nothing. Partly because he must have something so usually has some value in a check, and partly because players like this never bet/fold the river with a flush so often just stick it all in. Plus, from his point of view you could v easily have the nuts anyway. Damn annoying spot though.