My question involves an injury that occurred in the state of: California

So about 2 months ago i rear ended a 2002 toyota pick up truck...the back bumper was about 2-3 inches lower than usual..i was driving a 200 hyndai accent, a much smaller car, and my car was not damaged one bit...the guy came out and was walking around and everything seemed fine..he decides to file a police report even though the damges were way under 1k...the police man comes and explains that it was a minor accident and it doesnt have to be reported to the insurance, but the guy insists that he does anyways...he started to claim that his neck and back were hurting..and even got an attorney to send my insurance a letter in the mail explain the accident..infinty..im just very confused because the dmg on the car was very minimal..im not sure what to expect is going to happen..another important thing..i was driving a friends car and i am not under the policy as someone who should be driving the car...what do u think will happen? any help is great appreciated cause i am stressing out like crazy! lastly my insurance also took a statement from the policy holder and he said that he allowed me to drive the car on the day of the accident..what do u think will happen?

anybody can give me any insight or anything? please? thank you in advance i really appreciate it!