As a teacher myself, I'd tell the inspector-teacher to fuck right off. And then I'd tell the same to the other teachers who tried to excuse his behavior. I actually had a senior colleague who would similarly put students down like that and I called him out on his shit regularly, whether in class, to my superiors, or to other colleagues.
Being a teacher doesn't give you a free pass to denigrate students. Even if they break the rules, short of actually involving physical assault or bullying, it's our job as teachers to be empathic about their needs, anxieties, and concerns and not just be a gigantic douchenugget about TeH rUlEz. Hell, the rule itself is idiotic (makeup is far from some insignificant thing in adult life, so letting students have exposure in a controlled environment like school would be positive, not negative), so if it were me, I'd probably have looked the other way altogether.