Its clear here. You fold, looking at the number of hands that could have you beat already like q/9, any over pair a/j or sets, the risk versus reward wasn't there even though 15 outs twice has you damn close to even money. Nice laydown but if the situation was different, say stack size (if you were 1st to act) or short stacked, then I might have made the same move he made with a pair and a draw eventhough his was a gut shot and yours was open-ended.