Sounds like classic polygrapher BS to me. If you showed the same stress to the question about him wearing a watch, (which was obviously right in fron of your face), as the question about drugs, then its obvious the CVSA is equally as unreliable as the poly. 
     I had two polys and both said they had issues with my answers on prior drug use. I had previously disclosed the infro to my BI and the same info to the polygrapher, but they still thought I was hiding something so as a result, I got an inconclusive, and I failed the second one. There is not one day that goes by when I don't think about my experience.....

Seventh step of my 8 step process for law enforcement position was a CVSA. I rarely drink, have never had any problems with the law, pure driving record and most importantly am as square as they come when it comes to drugs. Never used them. Never been around them. Had to recall college experience as the last time I was even near them. That was 25 years ago. High stress was recorded on question concerning my selling of drugs. Re-test on that portion of the test after discussion with the officer showed less stress. Said he would write up that stress level was acceptable  after talking.

I was very angry after taking test. The was to be the slam dunk of the process. 400 applicants for 6 positions. Now down to 23. This faulty test may give the city enough of a reason to eliminate me.  The part most disturbing was that the stress showed up on the following question which asked me if he was wearing a watch. He called it carry over.