I was playing a match last night that went to a 10-point tiebreak. We were down 7-9 with opponent serving to my partner. Partner returns the ball from the deuce court high and sharply crosscourt with enough angle that the side curtains are making life difficult for the deep opponent. Ball bounces inside the doubles sideline. I was at net and shifted over to cover my alley. Opponent barely gets to the ball and gets it back deep. And that's when I heard it: "Out!" Opposing net player had called my partner's ball out when it was obviously in. She had a bad angle and was calling a ball while looking across a line, obviously, which is what caused her error. I am sure of this because I was looking down the line. I walked up and said something like, "Are you calling that out? Seriously? On match point?" Opponent said, "Hold on, hold on." She asked her partner, who said she didn't see it. There was some further discussion -- can't remember details. Then the opponent said, "Cindy, since you're sure the ball was in, you can have the point." I said, "I appreciate that. But since your partner put the ball back in play and you're changing your out call to good, I think we should replay the point. That seems fair." As I sit here, I am not sure I was correct. Maybe it was our point? I've never fully understood when you play a let when a player changes an out call to good and when it is loss of point. I know that when an official overrules a player's call in an officiated match, it is always loss of point, but how does this work when there is no official? Regardless, I feel OK about not taking the point. I went way past "Are you sure?" in challenging her call, and I have to give this opponent credit for being willing to accept loss of point at such a critical time in the match. I also think it laudable that she didn't just say, "I saw it out" and stick her hand over the net to shake hands. How should this have been handled?