In the match statistics, sometimes there is an Error credited to the computer even if he wins all the points! This has bugged me for some time now, but I found out why this happens. It happens on the last point of the match. If the CPU hits a winner on the last point of the match, the word "Fault!" comes up in the message box on the top of the screen. A split second later, the Match Statistics shows up. And even though the CPU beat me 7-0 in the tiebreak, it says he has an unforced error.
I have noticed this at the end of matches (after the last point is over), the word "Fault!" coming up in the message box regardless of whether there is an error or a winner.