I agree with the rep from AVIL. My reading of this legidlation is that it would have little impact on non-addicted illicit drug users who are the bulk of club drug users.
I think if your boss sacked you because he thought you used some E, you would have reasonable grounds to protest that provided a clear link between your illicit drug use and your work perfomance could not be made.
I do think we have much bigger fish to fry in the area of club drugs at the moment, and certainly there is some substantial discrimination which occurs and is likely to occur as a result of current media interest in club drugs.
Cheers,
Buck