I would not reveal presence of said camera until the next day when cooler heads prevail, or at least when the cops show up if I *know* I'm right. Unsure if that was uphill and the car rolled or if it deliberately disabled its backup lights.
Someone could easily just go grab it or even try shooting it out through the windshield.
Occasionally I will put my Atrix on the car mount and set it to record.
But, yes it can be used against you as well. That wasnt a mistake, but everyone makes them and it is a risk no matter what you do.