Objectively, which of Pac's catchweights were unfair?
De La Hoya - Pac jumped 2 weight classes for this fight. First time fighting at welter, coming off a lightweight fight. ODLH was the A side, he called the shots, so this was all on him. No issues with this one.
Cotto - Fighting for Cotto's welterweight title. Since Cotto weighed in the previous fight at 146, only 1 lb less at a 145 lb catchweight was supposedly fair. But if it's only 1 lb, why not just fight at the welterweight limit?
Margarito - Tony was a career welterweight. Plus, Pac didn't even come close to making the super welter limit. No issue with this one.
Marquez 3 - The catchweight was basically their real weights without having to cut weight and rehydrate. Pac is not a full fledged welter, more like a filled out junior welter who doesn't feel like cutting weight. He's the A side, so he can call the shots on the weight. No issue with this one.
So the only one I have issue with is the Cotto fight. Cotto had a history of trouble making weight for 147 as it is, plus Cotto was the champion. The others are no big deal for the reasons stated above.