Worst case scenario: the insurance companies might decide to deny your claim completely.
Perhaps they don’t believe you. Or they don’t believe their own insured client was at fault. Whatever the reason, this is not good news for you.
And even if they do believe you and do accept their own client is at fault… if you’re looking at a serious injury, in my experience insurers always try to hammer down the amount you’ll receive.
In either situation you’ll have to decide whether to take your case to court. Although that sounds scary and terribly serious, you shouldn’t be intimidated by it. In most cases, the insurance companies are testing your resolve as a tactic to enable them to get the settlement they want.