Kicking in the 90% range was risky even back in wrath when the same happened. In the spell batching thread itself blizzard confirmed behavior that says that the spell-school should’t even get kicked:
Idk what your problem is. You don’t like it?
Cool.
And if it is really bugged and blizzard was wrong, they will certainly have checked it by now, you’re not the first to claim that its off or whatever.