Ya at my company they stress repeatedly that if you issue a stop work there will never be a negative consequence if you don't use it excessively. They beat it into us so we know even the apprentices have the ability to do it if they think it's unsafe.

On the other hand I've worked for some who never even mention a stop work authority and you just knew if you did it you were getting screamed at.

I'm guessing this company was one of the latter ones.