I figured that out in the second paragraph when he said "drug test" - I think they'd have an awful hard time hiring engineers if they required drug testing. I don't do drugs (not even marijuana even though it's legal here), but I'd refuse to take a drug test just on principle - they are paying for my performance at work, not for what I do on my own time.

The only time I worked at a job that required drug tests, was at a transportation company where federal law required it.