That umpires and lines people make mistakes is the only similarity. They did it to Dementieva this afternoon missing one ball that practically walked into the front row seats as it sailed above the line and when I last looked she wasn't black.
Watts is old male and experienced - the girl today was young, female and inexperienced. Both are arguably dud but anyone who thinks thats proof of a global conspiracy probably believes Michael moore makes factual documentaries too.
the only common demoninator was that the other player did not do the umpires job for the obvious reason that you can't always see and there would be terrible trouble deciding if your opponent wasn't calling the lines because they were cheating or because they didn't see. as elise Bergen said no one would have called the ppint out in a tight match - things even out anyway and thats just what happens.
Graf used to give points back but she was usually up 6-1 4-1 when she did it and could spare 30 seconds before her next engagement.