Damage on the way up – Estimate, now expert of the insurance

Hello, my wife has driven someone at the rear light about 4 weeks ago. We have a Honda Jazz III, Bj 2010. After consultation with our legal protection insurance, or a lawyer at the hotline, as well as the opposing insurance (HDI) we had a cost estimate made by Honda. The tailgate has to be replaced, the bumper as well and also at the front is a bit bent (which you can only see on stage). o net estimated. You will say: “Why didn’t you turn on a lawyer directly”. Can’t I answer – except that we wanted to save costs. No matter… Now a reviewer’s office has called, which is supposed to prepare an expert report on behalf of the opposing insurance company. Why do they want to do this? If I was already in a specialist workshop, will the reviewer then find lower costs? And if so, what then? I don’t think that the Honda workshop will find any I have never had anything to do with this and we are a little unsure. What would you recommend? Many greetings Peter