You go RM for standing up to stuffy Hummer. For me, I would have cut down on the sarcastic tone a little and planted some personal situations in her way, i.e, "what if you were on the sidewalk with your kid and you saw a cyclist coming your way, would you walk on the street to get out of the way or just gotten hit?" and other scenarios.
But, the argument that you stated still got the point across very clearly.