Auto insurances disagreement on fault share - scenarios?

Question

Here is the situation in US, Washington state:

• a car collision happened between A and B
• a police made a report claiming that party A is at fault (not available to insurance companies at this point)
• B's insurance claims that A's fault is 100%
• A's insurance after talking to A driver assessed the fault as shared, with 15% on party A and 85% at party B
• A's damage is minimal, A has comprehensive coverage
• B's damage is substantial, B does not have comprehensive coverage

Basically, A's insurance has decided that they will only compensate 15% for B, leaving the rest up to the B driver out-of-pocket (since they don't have comprehensive).

B's insurance is instructing their client B to talk to A driver directly and convince them to convince A's insurance that the fault should be split more evenly, better yet 100% on A. "A" doesn't really care if their insurance pays off, as long as they are not personally held responsible.

1. We are the possible scenarios to resolve this?
2. Is my understanding correct that A cannot be held liable for A's insurance decision or any damages A's insurance refuses to cover?
3. Can B's insurance or client B directly sue A in this case or it would have to be an arbitrage between insurances?

Answer 1

This is not how insurance works.

The dispute over damages is a dispute between A and B; each insurer merely indemnifies each party for their costs in accordance with the terms of their respective policies. In practice, it may mean that the insurers resolve the matter between themselves.

A needs to be careful about not caring; an insurance contract is a contract of utmost good faith. If A were to deceive or mislead their insurer about the accident, then A's insurer could wipe their hands of the whole policy.

The way this gets resolved is for A to lodge a claim with their insurer, pay any excess and get their car repaired. If B chooses to sue A, then A's insurer will indemnify A and either negotiate or otherwise resolve the dispute (e.g. in court).

Answer 2

Car insurances try to run at minimum cost. The cheapest way to sort out an accident is usually that both parties tell their insurance what happened, and the insurance companies sort it all out amicably between themselves with a minimum of fuss. Doing that, each insurance company knows that they sometimes pay too much, sometimes too little, and that evens itself out. But avoiding litigation and expensive communication with their clients keeps overall cost down.

But in principle, the dispute is between driver A and driver B. Insurances like to handle all the disputes themselves because it is cheaper, but in principle it is between the drivers. The insurance cannot decide who is at fault. They can decide who they think is at fault, and they can decide how much they will pay without putting up a fight.

If one driver says "I'm not going to pay because my insurance is not paying", then the other driver would first talk to their insurance, which would talk to the other insurance, and most likely they would come to an agreement that keeps the cost down. If that doesn't work, then the second driver can sue the first driver. They should better be sure that the first driver was at fault. If the first driver loses the case, his insurance has to pay.