It does not need to be a DOT test. It literally can be a Breathalyzer, and if that pegs you get the DOT and get to check the reasonable suspicion box. That is how our lawyers explained it to me.
Ask the HIMS guys too, I know that they will agree.
Most airports are equipped to deal with this after the MCO incident a few years ago. Going to the clinic for a calibrated Breathalyzer is no longer required since most airport police stations now have them.
FWIW
Sounds like "your lawyers" didn't spend much (any?) time studying the DOT drug testing program. Advising you to go around the program that was put in place with all sorts of protections against using testing as "punishment" is insane in my view.
Local law enforcement can get involved, as we all now know, but dragging them into the issue, simply to get rid of the protections the DOT program gives pilots and force a test when one isn't allowed doesn't sound like a good idea.
However, you go ahead and do it. I'm not, I'll just simply give a hard look and continue to say, "We don't joke about that."
The pilot's unions spent a lot of time back in 1989 and 1990 ensuring that as the inevitable Reagan-era big brother drug and alcohol testing finally hit the line pilots, that there were lots of protections and procedures to keep it fair.
25 years later, we have bright sparks trying to throw all of those out the door to prove a personal point against a boor.
If your company lawyers are telling you to do something outside of the regulations (Part 121, appendix I and J) you, and your union, should think really hard about the end results of this. Are your company lawyers on your side, or do they have a different interest at stake? I know the answer.