Is there any way I'm wrong here?

[redfisher]

I flop bottom set on the flop. I lead the action on all streets, with turn and river headsup with me and the player to my immediate left. After a relatively large river bet/call, my opponent says "If you have AK you win." Since I beat AK, I show him my set without tabling it. He instamucks, I table the hand.

Nobody said anything, but could a player not in the hand have an issue? At the time I just thought it was good form to let my opponent know he lost first, but I pretty much voided the other players rights to ask to see all hands.