Why insurance claims for soft tissue injury are so critical?

A Lowe's employee was cutting plywood. He lost grip of the wood from behind and it flew into my left side knee and I covered my face and my left forearm and wrist bone got bruised and cut. I went to VA ER doctor they gave me pain killers and muscle relaxer. I plan on going back because of the pain. It caused me anxiety. Do I just contact the insurance company. There is definite negligence. The safety officer was there and they conducted an incident report but would not give me a copy. They said when you get a doctors note give it to us and we will give it to the insurance company. Can I negotiate with the insurance company and can they deny me the incident report. I have pictures and a video of the worker who caused my accident.

In my accident my car was totaled and I suffer with soft tissue injuries. Medical expenses are over 4100. They are offering 8000 is this fair