With Oil Can, it's hard to say. He's an unreliable narrator. He said that he found out he wouldn't pitch Game 7 the day of and ran off and cried. He had a known drug problem and maybe Mac saying "he was drunk" was a polite way of saying he ran off to do crack to help cope. He had a very volatile season (Can Film Festival, 21 game suspension after a run in with Rice and leaving the team all due to not being picked for the All Star Game, injuring his arm in a tussle with the cops). If we believe that he was using substances to cope with his problems throughout the season, it's not farfetched to believe that he was hurt enough to do something stupid prior to Game 7 after hearing that Mac was going to start Hurst instead.