I have a confession to make. Last weekend I broke the code. I was playing socially - so not a match or anything. I was receiving serve and the 1st serve lands a good 2 inches inside the line, I would bet my life on it being in, but my partner (who is looking down the line she was calling) calls it long. Immediately our opponents smile and ask are you sure. She says that she is absolutely positive. She was probably trying to save face. After saying she was sure, I suddenly couldn't bring myself to say it was 2 inches inside the line. I kept quiet. I like to think that if it were a match I would have said something. If in this situation again, I think it is best if I immediately correct my partner since if they then confirm the call to save face, it is 10 times more embarrassing to overrule them.