Auto body repair & detailing: bumper, luck mark, mall security

Question
I was in a mall parking lot and hit a van at the right back bumper.  There was no stop sign or marked street that I would have known a road went thru the lot.  I was going 5 mph and hit the brakes.  I barely hit .  No damage to my car whatsoever.  The couple in the van had previous damage to their van and called me stating I should not be too shocked at the large amount of money I will have to shell out because of extensive damage to their van.  They told me I should get a ticket for wearing flip-flops while driving because it's against the law in CA.  A police officer told me this was untrue- he laughed.  What should I do?  I called the mall security  

Answer
Brenda-

This is what you pay your insurance company for. Let them handle it. They will investigate the claim and if you are liable they will pay the damages- they will not however pay for any prior damage. If you don't want to involve the insurance tell them you will pay only for the related damage- no more and no less. Challenge them to come up with an estimate from a shop for the damage that you caused, I bet they can't do it if what you say is true. Good Luck- Mark