Surely the main causal factor for the engine failure will play a part in the calculations or computations - yes.
It's the unexpected consequences you insure for. The more unexpected the cheaper the insurance per coverage
Hypothetical example: FOD to blading is often absorbed by many (not all) airlines while wear induced part failure may not be insured by most.
The consequences of FOD or most blade failures may not be insured up to the aircraft level like pylons. At that level the insurance may kick in.
There is very little to do with blame other than behind the scene divvy up between multiple insurance risk takers in a consortium. In the end the insurance may go up for both the engine manufacturers (plural) as well as other aircraft manufacturers. It's often too difficult for the insurance carriers to redo risk based on one or two events.
Message:As a manufacturer show diligence and you pay a lower fee than your competitor (its hopefully a very small percentage of your total sales)