In our class we were told to say "Call for Domino's". But in the heat of the moment, trying to remember everything else to do in the drills, a "help" or two definitely slipped out of my mouth. I immediately followed it with a "This IS a DRILL, repeat, this is a DRILL, I meant call for Domino's". The instructors did intentionally 'trick' us by pulling a drill when we were told to ungear and half-unprepared, in order to try and simulate the not-sitting-around-waiting-for-it nature of real emergencies a bit, and it did get the juices flowing.
That, and the rescue classes do try to stay in the 'back' away from most of the divers, since recovering a diver down often also stirs up the muck....
I agree we should all do what we can to not desensitize divers to real emergencies. But short of only permitting drills on different days entirely (? is that possible - negotiate to have the place opened one weekday a month or something for rescue classes??) I don't know how to avoid the 'urgency' of the call still coming thru in drills regardless of the words......"you play how you practice" so just pretending too passively and quietly is just not really testing you.