Quoting Princess.:" <blockquote><b>Quoting Chuck Bass:</b>" It depends. I worked for one company that had ... [snip!] ... for the position. My husband just thinks his father is saying nonsense, an doesn't want to contact the employer again."
It never hurts to ask. The reason some companies are more lenient about THC is because unlike harder drugs (cocaine, meth) an employee could use it recreationally on their own time and, while it may be illegal, it wouldn't really affect them on the job as long as they didn't smoke it right before work. Also if someone was a frequent smoker, it could be in their system for a while and it could have been weeks since the last time they smoked. Harder drugs that test positive were used recently, usually within the last 3 days, and have a higher incident of severe addiction that would increase the likeliness of an employee coming to work under the influence.
If I was him, I'd call and ask. Like I said, it doesn't hurt to ask. The worst they can do is say no.