margarito actually weighed in a 2-3 pounds under 147 limit against Mosley. His idiot trainer, in the hotel, had some crappy scale and they didn't know at the time but it was wrong - it was saying margarito was about 5 pounds overweight. They drained his ass for about 3-4 days, still he couldn't get below 147. That's why, at the weigh in, they were all shocked and cheering when he was weighed in waaay under 147; they all thought he'd be over weight. Their scale was broke and they drained him for no reason. Meanwhile, shane actually came in a bit over at 147.2 and an hour later or so came back and weighed 147 on the dot.
So, there is a little bit of truth in that Margarito probably wasn't physically 100% that night. Would that have changed the outcome that night? Unlikely, but if he looked weak and fatigued, that may have played a significant role. Mentally, getting busted with loaded gloves I'm sure could have a negative effect as well.
What does this mean for pacquiao? Well, it could mean nothing, but on the otherhand, it could mean a lot of people are severely underestimating Margarito because of one fight against Mosley. Prior to the Mosley fight, let's not forget Margarito was considered the best fighter in the world at 147 (while floyd was on vacation) and was on an absolute terror prior to losing.
And I agree with Rumpelstiltskin, in that picture Margarito is clearly 170+ pounds. That's always been his walk around weight and on top of that his last fight was at 154 pounds (not 147).