The only thing I have an issue with is that an employer should be able to keep people from coming to work stoned. I understand the complication with the medicinal aspect, but if I had an employee whacked out on prescription pain killers or what not, I'd like to be within my rights to send him home. There are plenty of jobs where it wouldn't matter, but plenty where it would.
Now, their phrasing of "marijuana in his or her system" isn't helpful. THC stays in your system for a very long time, but the effects are obviously short term. That's why I take issue with any article that reports on a driver in a fatal accident as having pot in his system (one just the other day in Cali). This is one of the many ways outfits like MAAD distort facts.
Lastly, the cop's concern about driving under the influence probably is misguided (can't say that I'm surprised). Studies show that people who are high aren't as good at driving as straight-headed people taking the same test. However, we're talking about a minor difference here. In normal, everyday circumstances, I'd put stoned drivers ahead of the average guy. The overwhelming majority of drivers suck, quite frankly (and that includes all of us at times). Rarely do people devote enough mental resources to good driving habits. Stoners do.