Excuseable reasons for failing drug test?

Most drug test will tell exactly what drug is showing up and those drugs aren't in OTC cold medicine. Usually a drug test is looking for meth, marijuana, heroine, cocaine,etc. Most people who try to say that type of thing think they can pull the wool over the eyes of the judge and the CW because that's what they have been doing all their life. It won't work for them this time.