That is what an insurance company lawyer does. The police issued a report against you. If he goes to court, assuming no other evidence you are responsible for the damage. How much the other side can recover is a separate issue but you are at fault. The attorney will always make a bona fide offer to settle the case. Based on what you said, he has not done anything wrong. He is not there, not a witness, and he cannot change the police report. There is no guaranty the other side will not recover the full $160-170k. You can try to schedule an in person meeting with the attorney to find out how much evidence, like medical bills, the other side incurred and why they are seeking to recover that much.
You also have very right to seek a car accident attorney to represent you. No matter what you do, do not go to the court per se. There are so many procedural and evidentiary issues for you to handle, as far as I can see. For example, what if the other side wants a jury trial? Do you know how to do voir dire? You may think you can save some attorney fees but at the end you will spend much more than that. I have seen so many cases happening like that.
At last, if you really just want some legal advice not the service, there are forums available, such as avvo.com, freeadvice.com, or lawguru.com, where you will have licensed attoreys in your area to answer your questions, without incurring attorney-client relationship.
This forum is for opinions only not legal advices. Correct me if I am wrong, Mr. Cat.