I, too, have a dash-cam installed, front AND rear-facing.  It's already paid for itself from claims that something was my fault, when it wasn't. But without video proof, it becomes a he-said,she-said issue.  Insurance companies don't care.  Your own carrier simply charges you more, because YOU couldn't prove you're innocent.  I've even switched insurance carriers when they wouldn't agree my video evidence was enough.  Fortunately, the courts agreed with me.
An interesting outcome, is that I think I am driving more carefully WITH the dash-cam.  So it's a win-win for everyone.  Except the ones who get caught being stupid......