one head to a hand. if that guy can't properly read his hand it's his fault. had you not said anything he would have folded and the trips man would have gotten the pot.

but, since it wasn't technically a "fold", the hand was still live and he only needed to show his hand to claim the pot.

the guy who lost has the right to be upset with you since you cost him the pot, but since it was a friendly game it should be no biggie.