At least this settles they can't be trusted for anything, can't actually learn. No matter what, they will keep doing the same things, for their own purposes. They simply don't understand what the words mean, and it's become clear that illness is an experience that absolutely has to be experienced in order to be understood, as fully as it's almost always needed to actually play an instrument in order to be a musician. And the only exception would be conductors, and they usually are musicians anyway. Just knowing about sheet music doesn't make one a musician.
Obviously, though. It's possible to go from being wrong to getting it right, but not from a position of denial. There is no half-way between reality and denial of reality that works out in real life.