That depends entirely on who caught you. If it's, say, an angry neighbour that knows you all too well, you run like hell. If it's someone who is unacquainted with you, you can either miraculously forget how to speak English ("Non parlaiz Anglais, monsieur. . . "), or you can talk your way out of it ("Yeah, I was on my way to my grammie's house, but I got totally lost and was just trying to find my way back. . . ").