Colabello probably shouldn't have bought those Vitamins from Ang.
Who the hell knows if he intentionally took something or not. Multiple guys getting nabbed for something they would have known would be easily detectable makes me think some supplement was tainted or something, or the players didn't do their due diligence before taking a supplement. They're still at fault if it's the latter, but at least there no need to make them villains or something. If it's the former, then players should always keep a few pills from each bottle to be tested just in case something popped up.
If he took the banned substance intentionally, then he's just an idiot.