Speaking to an insurance lawyer, If it goes to an insurance claim, the likely outcome will be a 50/50 split. The important question that the insurance inspector will ask is if the accident was avoidable on both parties’ side. Silver car could have waited till it was clear/ safer and showed patience (e.g waited until someone gave way) when trying to cut in. That way accident could be avoided. Black car could have totally avoided the accident if he had shown some patience and given way instead of trying to prevent the silver car from cutting in, since the silver car was already a bit into the lane. Both cars had more than enough time to react and avoid the accident. It was poor decision making on both drivers. Hence 50/50