As per the first thread, you and the other party had mutually agreed that he won't lodge a third party claim. Neither surveyor nor your insurance company participated in this discussion, so they don't know what is agreed (they just know what you told them). As per the insurance policy, you need to inform the insurance company and will have to take all the decisions with their approval.

There are lots of fraud cases, where the other party later on went on and lodged a third party claim. So the insurance company is safe guarding itself. I would suggest talk to your surveyor and solve this matter.