If you "fail" a lie-detector test, they always say it proves you are guilty.
If the results are inconclusive, they say the test raises more questions than it answers.
Bottom line, you can't win, you can only lose.
Very true, I attended a class about polygraphs taught by and ex-polygrapher.
He explicityly stated that you should NEVER, EVER agree to take a polygraph. Interpretation is the key failure, the tester is NOT your friend, just taking the test generates so many negative signals to the equipment.
You’re nervous to begin with, increased BP, heart rate, respiration and galvanic...etc. all = FAIL.
I can vouch for that, a number of times. All they do, is measure body responses.