Malignaggi expressed those reasons a long time ago, he has legitimate reasons to dislike Pacquiao. I'm somewhat past it, well depending on the day I guess.
He doesn't like the fact Pac acted shady about the drug testing years ago. As I recall, around that time Paulie was one of the few boxers who were willing to call Pac out on it being fishy refusing drug testing. Everyone else, especially the boxing media tried to make it a non-issue. It wasn't until other boxers started requesting it that Pac received criticism from more sources besides Paulie and Mayweather's camp.
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