Auto Insurance Claims: accident with cab door, taxi commission, cab company

Question
As I was driving down Michigan ave in downtown Chicago a passenger opened the door of a cab into my truck damaging the whole right side from front to back. I called the police and me and the cabbie both filled out a report at the closest police station.
    Today I received a phone call from the adjuster for the Cab company's insurance. The adjuster on the phone stated that since the cab door was clearly marked "exit on curb side" and the driver stated that he informed the passenger "to exit on the curb side"(FYI** believe this to be untrue based on what the cab driver told me that night) that the Cab companies insurance would not take any fault, and that I should contact my insurance and file a claim if I want to get my truck fixed.
   Now I had an officer come on the scene that night because of the unique circumstances of the incident.  I asked the officer if I need to get any information from the passenger that opened the door and he told me "No when this happens it is the cabs fault"
  So my question is who is at fault the cab company? or the passenger in the cab? Is this just a tactic to try and lesson the number of claims by the cab company?
    There is almost $3500.00 worth of damages to my truck. And I do not want my insurance rates to increase because of an accident that I was not at fault for.  

Answer
Hi Jeff,

Unfortunately, I'm not familar with Illinois law. You should pose this question to an attorney knowledgeable in this area.

You might also contact the Chicago Taxi Commission. They may be able to tell you who would be at fault in this situation.

I hope this helps
Richard Hixenbaugh