Boxers aren't saints, and I assume Lewis, Holmes, Holyfield, Frazier etc had a few drinks or a few tokes after a hard fight. Key word is after. Hell, even the Klitschkos may have had a few vodkas.
But according to sources, one of which is ex-wife's Nova's book, The Spinks Jinx, Leon did alcohol, pot, coke basically nonstop during training and the day of the fight. Even if she's lying half the time, Spink's party escapades are well known.
Was Leon a crude amateur who was never that good? Or could he have been a great fighter? Also, he fought Ali, not to mention LeDoux and Righetti way too early.
If he had even a modicum of disciple, how different would his career have been?