How do you know MNW and Pirate aren't in cahoots? Perhaps the actions MNW took gave time to pirate to take care of his own personal obligations first during the initial chaos. Why couldn't this be the case?
That... would be too scammy of a thing to do even for Matthew

Do you know him? Does anyone know him - for fucking real? Didn't some of these PPT guys actually meet Trendon in LV? Or was that total bullshit, too?
From my interactions with him over the course of the year, Matthew never struck me as a rude, inconsiderate asshole (pirate definitely did). At most Matthew was always a somewhat insane weirdo with a severe lack of maturity, and excessive trolling tendencies. I may be wrong, but his character definitely did not fit the profile of someone who would team up with Pirate to purposefully rob people like that (I'm still of the opinion that he chickened out on the bet or something, which is different from basically premeditated theft.)