The difference is that there are strict rules in place for testing positive for various drugs (including weed).
While no one wants a sexual predator around, it would have to be proven. He has allegations against him and they are investigating, but no charges havebeen made. While this looks bad, if you eliminate anyone with allegations made against them, you make it easy for competitors to get rid of their opponents. I'm not saying it would happen often, but it would definitely happen.