So, if said applicant told you up front what the deal was, in detail, the failure of the drug test would not present a problem ( unless it was operating heavy machinery, or driving a truck )....?
We sent people to DOT regulated sites. The drug test would specifically screen for that drug along with others.
Proof of that drug only would not result in failure.
The test gives more complex results than overall pass/fail, although p/f is usually the only information shared unless specifically requested in advance.
We did not have people operating heavy machinery, but they would be walking around in areas where heavy machinery was routinely in operation.