Scum recruit scum and scum will always turn on each other because that's what scum do. No scum involved here is to be trusted. Some scummy accusations will be true and other scummy claims will be lies.
Gordon is clearly no angel, he was verballed to Illinois, denied multiple reports he was switching to IU. Then Sampson hired 2 coaches with ties to Gordon, one was his AAU coach, one coached his dad in HS, and surprise, Gordon switched to IU.
My guess is that Gordon just got tired of people talking about his 2nd half fade and how IU collapsed after Sampson got canned. If you assume he's telling the truth and some of those kids being benched and suspended last year were being punished for drug issues, it sort of makes it a lot easier to understand why IU fell apart after Sampson left. It wasn't just that they missed their coach it was that the guys in charge were trying to curb that drug issue and suspending players hurt the team.
So while there is the element of thrown under the bus, especially since he didn't name who was on drugs(so some who weren't will be suspected), I think it's mainly he wanted to explain why that team fell apart.