I thought the 10-point "must" system meant that one of the fighters must win the round?
That's an old wives tale perpetrated by the UFC and Marc Ratner specificly. The Unified Rules clearly allow for 10/10 rounds in the advent that A)There is no clear offense by either fighter (think the first two rounds of Mir vs. Cro Cop) or B) that the offense from each fighter is so close that it is impossible to discern a clear winner.
The UFC (and specificly Marc Ratner's) position on the matter is that the judges are paid to descide a winner. They are of the opinion that 10-10 rounds are for slackers and that anyone can score a 10-10 round. They're afraid that in any fight where the action is anything near close, fights would be scored 30/30 or 50/50. Obviously, that line of reasoning is a bit silly.
Brian.