> The difference is that ambulances/police are allowed to break the rules in an emergency - famously, ambulances have a legal right to speed and run red lights in an emergency, and cops obviously have a right to trespass.
I think this is just a way of saying that they are not breaking the rule, simply because the rule doesn't apply to them.
It's more complex: in many countries if an ambulance hits a car while running a red light because of an emergency, the ambulance is at fault, as they were breaking the rules.
So the rules still apply to them, they just won't be pursued on theoretical grounds (getting fined/arrested sheerly because of the infraction, without any other consequences)
I think this is just a way of saying that they are not breaking the rule, simply because the rule doesn't apply to them.