I watched at Derbycon multiple times someone that could make a polygraph test do whatever he wanted, otherwise he was a murderer that murdered himself and it all happened before he was born. The test was being administered by a long time veteran polygraph operator who had recently retired.
I don't know what that means, because a polygraph by design tells the polygrapher whatever they want it to.
If the demonstration was performed in some blinded protocol then perhaps there was more room for ambiguity in the results than usual.