Unlikely, sure, but not impossible... I've seen more than a few instances of road rage that turned into news stories.
Its also pretty unlikely that your gun will go off when you don't intend it do, that somebody will break into your house, that you'll win the lotto, or that you'll be hit by lightning... yet we still use safeties, lock our doors, buy lotto tickets, and nobody in their right mind will go stand out in the open in a lightning storm.
As a CCWer, we need to think about the "what if's" and avoid situations that could put us in a position to make somebody's day take a very bad turn, no matter how unlikely. There's a line I heard once.... "when you carry your gun, your middle finger stays at home."