Not sure how many others have experienced it, but the occasional person in a club I go to has the adorable habit of apologizing for losing the point when I was really at fault. What happens is I fail to go for a shot that should have been mine. They are forced to quickly make a mad unsuccessful scramble for it. Even someone like Kevin Sanjaya probably couldn't have got to the shot. Yet, they then apologize for losing the point! While it isn't necessary to do this, I appreciate the gesture.
Some of us, like me, have the habit of apologizing first whenever a point is lost to ease the tension for ourselves or our partner. There are also times we apologized because the previous shot from us is of low quality, resulting in easy kill from the opponent.