I doubt that Riddle was not training. I know a number of guys that fight in the UFC and what they do to train for their fights. They are in crazy shape and still at times get gassed during fights. If Riddle wasn't training, he could probably barely get out of the 1st round. He probably does smoke every day. If I had access to that type of herb, I would too.
I don't know that I would agree that taking PED's while training is ok but being at "acceptable" levels for the fight. Isn't that pretty much the definition of cycling?
Why would it matter how hard a guy trains when factoring in why they get cut or not? Isn't what really matters is whether or not they win? That's really what the barometer should be. Understandably the UFC wants exciting fights too, but the fighters need to be smart about the match ups too. Now, I didn't see Riddle's fight against Mills, but from what I have read it wasn't his most exciting fight. If you're going against a more polished striker and you can tell from the beginning that if I stand with him, its not going to end well, you go to what is going to win the fight correct? That's what Schaub did against Johnson.