I know this will sound like a true stereotypical story but it's true and reminds me of when I was driving up through France and stopped in a service station to fill up.
The guy in front of me in the queue to pay was English, he made absolutely no attempt to even give the pump number in French let alone anything else as he got louder and louder the guy behind the kiosk just kept shrugging his shoulders saying "Je non comprande pas"
I intervened in my very very basic French and got him served.
My turn, right then here we go. "Yes my friend, what can I get for you?" he spoke perfect English.
This happens a lot and not just France. If you have some moron you don't like the best and easiest way to annoy/frustrate him is to roll the shutters down on the language. Seen it happen numerous times.