That is a worry, Lexair. Instructors work under a HOO whose job it is to ensure that incorrect presumptions aren't made and that instructors are allocated jobs they are qualified to do.
I once worked at a school where they had an unsupervised Grade Three teaching night VFR at a remote base with no suitable alternates within an hours flight time, so this sort of thing did happen.
In this case it could be legal if the guy is doing supervised night circuits. People do 5 hours of this so they can do IFR at night, but 90 hours? Surely 90 hours of night circuits would drive anyone insane however badly they want that ATPL.