Just watched it now. Tbh, I think its a fair test. On one condition though. If her first (Standard) time was set on her very first lap then the test is null and void as with every other lap it should see her improving to a point.
If her first (Standard) time was set at a point where she was no longer going any faster then its valid imo.
Remember the Topgear where they set James May a challenge of going 10 seconds faster with instruction from Jackie Stewart. You will reach a point where you can go no faster on your own without help. Whether it be in the form of modifications or driver training.