Boyfriend's Urinary Drug Test Mishandled By A Nurse, Possible Discrimination

My boyfriend had a pre-hire physical scheduled as a returning worker to a company we are both affiliated with. This of course includes a urine cup test, neither of us do drugs and use marijuana once a year on 4/20 (we are in Washington state), so we were not worried at all about this test. He does the typical emptying of pockets into a lockbox and the search before going to the bathroom to pee in the cup as well as the toilet with urine indicator dye in it. Typical easy breezy urine test, except it wasn't. The nurse claimed to not be able to get a reading and immediately became hostile, accusing him baselessly of using fake urine. And when I say hostile, I really do mean a completely unprofessional codeswitch. She put her nose to the open container, smelled it, and exclaimed "this doesn't even smell like pee" while continuing to accuse. He offered to give another sample in 20-30 minutes after drinking a bottle of water, she denied him and proceeded to kick him out of the clinic without any documentation or explanation being given to him besides professing "you are using fake urine".

I went in myself and calmly asked the front desk receptionist what was going on, I then turn around and the same nurse is standing there. She told me to get out, and that he can sort it out with the company. My company is now telling me my boyfriend is no longer hireable, because the nurse delivered a positive test result instead of an invalid one that would lead to a reschedule. That conclusion doesn't make sense, how can someone deliver a positive test result if no proper reading was made? I think there is a chance she may have profiled my boyfriend using her own bias based on his skin color and appearance, and decided to deliver that result to spite him, which is now having consequences with our employer. I also worry about other people going there to get a urine test done by this woman, who is clearly too incompetent to use a sample cup and PH strip.

As proof, I took him to a different branch of the same occupational health clinic for the same exact test within an hour of the incident, and he of course passed and the staff was baffled as to how the previous nurse arrived at the conclusion she did. We thankfully have the passing test in writing.

Is what this nurse did illegal? Is there a specific office or board or something I can report this to? This feels incredibly unjust and we just want to go to work