I have a legal question?

I was returning my loaner car to the dealer, as i was driving through the the service lane, there was a car to my right, i was waiting on him to close his car door do rthat i can proceed on driving forward. When he finally close his car door i proceeded to drive only a few feet and i apparently ran over his backpack that he had set down in my lane. He claims that i was my fault because i ran it over. However it was out of my scope of vision when he set it down because i was pulled up only within a few feet whn he set it down in my lane, of a sevice lane mind you. where cars drive in and out for service. I gave him my name and phone number and i refused to give him my drivers license number because its not a car accident. he even threatened to take me to small claims court because his navigation broke inside his backpack. I offered to pay half and he would not accept. he also threatened to take me to his insurance company and now he's threatening to FILE A HIT AND RUN REPORT to the police, because he wants me to pay all of the cost to repalce his navigtion. What should i do? please help?