I suspect this might be loss-adjusting. Loss-adjustors are employed by insurance companies to investigate claims, and usually seem to be keen to adjust the claims downwards.
If you don't like the loss-adjustor's decision and the consequent proposals of the insurance company there may be a mediation process available to you in some cases before you go to court. When I had such a row with a company I got the impression that it was a matter of either accepting the claim or going to the county court. I threatened the court and the company settled the claim as I had interpreted it, but I think I was lucky.