It could have been a lot of things. You can take certain cough medicines, or cold-related relief medicines, and get popped for "substances."
Happens in the UFC too. Those guys cannot take certain medicines or they get popped. Sucks big time...considering the good stuff for clearing up a bad cold or the flu or whatever contains drugs the organization deems non-permissable.
I will reserve judgment until (if at all) we learn more. There is a wide array of things it could have been. He doesn't seem to be a druggie to me. But who knows?
SheTexan: I never would have pegged you as a Turk fan over Hartmann. Hartmann has those looks and the skills, what does Turk have that makes your eyes twinkle? An AARP card? Just kidding! Don't neg rep me! I Luv u! LOL.