Man, the more you learn abot this guy the worse that it gets. McPherson had crashed two planes prior to this fatal crash. And there were a ton of other warning signs.
Whether or not they knew that his license had been revoked, it’s amazing that any flight school would hire this guy. Even if they didn’t bother to look up the public records available on his flight history and license status, wouldn’t they at least contact previous employers (“oh, that guy who crashed our plane? Nah, we can’t recommend him”) as well as have someone fly with him once or twice as part of the hiring process as a basic sanity check to make sure he was an ok instructor? If they had then they would have probably seen the red flags that the FAA had seen on their check flights with him.
And as the video notes, the FAA screwed up pretty badly too in failing to revoke the instructor certification and contact the flight school, as well as doing a poor job in putting together their investigation.
In my experience the number of would-be commercial pilots and flight instructors far exceeds the number of job openings (or at least that used to be the case when I was flying) so there really should be no reason why any flight school would feel pressured to hire anyone who was less than fully competent.