I dunno, after watching the fight several times, I've gotta say the decision was going Renzo's way, but Shamrock was definitely causing more damage. I agree with the DQ decision - I hate that that's how it ended, but rules are rules and at any time if you break the rules, your opponent can DQ you. Honestly though, the way Shamrock was using his hands, a KO was a definite possibility. On the ground, Shamrock was causing more damage but Renzo was definitely controlling it, so yeah, I'd have given it to Gracie if the fight continued.
Ahh well, but what a way to break a no losses streak.