it doesn't say he was his trainer. It says he trained him. Once, for free, is enough for that statement to be true.
I've never understood why you are such a defender of the status quo. Someone says something negative about those in power, you jump to their (those in power) defense. And you're so quick to degrade the underdog.
I trained with Charles Dixon years ago when we were both at Golds Gym in Greenville. Does that mean that I can all of sudden put down on my website that I was the trainer of IFBB pro Charles Dixon?

Uuuuh No....
That type of thinking is stupid. Let me put it to you this way so you can understand......If you take a guy home from the club and sleep with them, does that make him your boyfriend??? No......

Its no different from that guys that claim to be the trainers of IFBB pros when all they did was casually associate with them such as help them put more weights on the bar or put his food in a microwave or etc.
You should only take credit for what its ACTUALLY WORTH.
I'm not defending Dan because he did the same things that Joe did and Joe just happened to win.