If, after taking the video into account, the NCAA concluded that her departure was in substance involuntary (regardless of the euphemisms used by both Geno and her to describe it), then granting a waiver was a reasonable decision. I believe the purpose of the "sit out" rule is to give programs some stability and some protection against players transferring on a whim, but if a player leaves after a coach (in one way or another) lets her know that it would be in her best interest to leave, that is another story entirely.
I agree that the waiver might not have been granted if the video did not exist.