I had an overfilled tub that resulted in a similiar result however much smaller (~8k in damage). I talked to the people who fixed it and they had an extremely set process to document everything and satisfy the insurance company. I suspect its less that they fight but more that they set the market price for repairs. Multiple worksheets from various insurance groups to document the moisture content, square footage affected, pictures, etc.

Totally agree. There's the obvious part of insurance: If there's a 1% chance of something bad costing you $1000, you can buy insurance for $12. Then there's the less obvious part, which is that the insurance company might only have to pay $900 for the same risk that would cost you $1000.