This is not true. It's a requirement in many states' probations that probationers undergo regular polygraphy. If they fail the polygraph enough times, they get kicked out of state-mandated therapy and are violated.

Thousands of people are in prison right now over failed polygraphs.

In places with strong courts that won't put up with this, probation officers simply tell the therapist to write up the probationer for some other, vague non-compliance issue should they fail enough polygraphs