Lie detectors measure physiological changes and not an actual measure of truth; she could have been lying about a gangbang. Besides, the stress associated with having to take one of those next to your mother knowing the questions are going to be embarrassing would throw the entire premise of the test off balance due to the stress you are feeling before it even began. If the baseline survey was taken before the mom entered the room; the validity would be dubious since the control questions took place in a different environment. This is why lie detectors are only admissible in some courtroom situations. I AM THE TRUE BUZZ KILLINGTON!
Unless it's a situation where the questions were asked beforehand in a controlled environment and this second test is just for the reactions using the first test results. That's how they did it on that horrible FOX game show.
Where am I needed?