Umm...I think the commercial was about the dude getting a call from "Tim", then Tim probably asking if he had a good time with Tim's sister (or girlfriend), and the dude replying that yeah they had a blast and he was high. Then Tim probably asking him if he knew that he had raped the chick, and the dude saying, "What? Man, you know I wouldn't do that, it isn't me.." and Tim hanging up.

Haven't seen the commercial for a while, but yeah.

It's anti-drug, so of course they would use a commercial that would make the viewers bring up their own opinions of what most likely would he have done wrong if he had done weed. It all depends on the point of view, thus making the viewer think that because you smoke weed you are going to make bad choices.