Auto Insurance Claims: At fault, work with their insurance or mine?, license plate frame, dust patches


Question
I rear ended a $200,000+ car at a very low speed (~ 1 mph).  The car had stopped for a red light and I looked away for too long, didn't hit the brakes as early as I should have, and bumped the car.  The driver was pleasant and we looked over the damage to his car together.  I did apologize at the scene because it was clearly my fault.  I cracked a letter in the license plate and left a few dust patches and superficial scratches on the bumper.  We agreed that it may be possible to buff out the scratches.  The only damage I saw on my car is a slightly crooked license plate frame.

I gave the driver my name, phone #, driver's license # and insurance name.  I had proof of insurance with me, but was flustered and mistook my registration for it.  I went back to my car to get the proof of insurance, but the driver said he could get it from me later, so I did not give him my policy # then.

His adjuster left me a voicemail stating that he is conducting an investigation of liability into the accident and asking me to return the call.  Should I return the call directly or go through my insurance?  If the repair cost will be minimal, I am under the impression that I should avoid notifying my insurance.  However, I don't know a) whether the adjuster has already contacted my insurance, b) how to tactfully determine the cost of the repair from his adjuster, c) whether I am being paranoid in wishing to leave  my insurance out of this or d) whether I expose myself to unreasonable risks by not speaking directly to my insurance company.

I have had my policy for 9 years and have never been involved in an accident or had a citation.  I only have liability insurance on my car.  Any suggestions are appreciated.  Thank you!

Answer
You are likely required per the terms of your insurance policy to report all accidents in a timely manner.  If you fail to notify your insurer and the lose their right to handle the claim properly, they can deny protection to you if a claim is presented later on.  

The reason for this is that few damage claims are ever what they appear to be on the surface.  The "light" tap to a bumper is a perfect example.  Bumpers are designed to absorb some impact, but very often allow additional force to be transferred to the hidden areas behind the cover.  
Ironically, this occurs more with the high dollar cars than with the ones that most of us drive.

Some bumper covers are repairable and some are not.  The bumper cover alone on a car in that price range could be over $1,000, just for the part.  If it's repairable or not, the shop may need to blend the finish onto adjacent panels for a perfect match and $200k car paint work can get very high.  This may sound like the worse scenario and may be.  It's possible that the car can be repaired for under $700.  I'm just giving you a range because I can't see the car.

Now, the reason that the insurance company needs to handle this right away is that the car is still likely being driven.  What if this guy backs into something tomorrow?  What if someone else runs into him or bumps his car in a parking lot?  How would you or your insurer prove what is your damage and what is not?  What if he sells the car and then presents a $5,000 damage or diminished value claim?  Should your insurance company be responsible to pay that when they were never given the chance to inspect the car?

I'd report it right away.