The commission is retarded. I am a former pothead, and the only thing it does is make you indifferent. In my experience, any numbing effect would be greatly overshadowed by the lethargy that it would likely cause.
I saw that he tested at 175, with 50 being the limit of definite usage (beyond 2nd hand). However, the worst quality of weed is that it takes a very long time to clear out of the system. It is stored in your bodyfat, so athletes would clear faster. If Diaz is a chronic smoker (pun intended
), he would have extremely high levels, even if he hadn't smoked in a week. People always say, "Yeah, weed stays in your system for 30 days." This is like saying, "alcohol stays in your system for 3 hours." The length of time the substance is in your system depends on the amount and frequency of consumption. If you drink one beer, it is metabolized in approx. 1 hour. If you drink 37 (I have a friend who actually does this), it's gonna be sticking around a wee bit longer. So if Diaz smokes 2-3 times every day for six months, he'd probably test above the cutoff for 6 months. If he smoked once, he'd be clear within a week.
My wife had to take a drug test 10 days after I stupidly got her high (apparently not a good idea when you're job hunting). She is athletic, and hadn't smoked for a while before that one instance, so she passed.
All that being said, a high level could also be indicative of being high during the fight. I just can't imagine an athlete at that level would fight high. The potential for paranoia would be too much for me, and THC decreases maximal workload capability.