1, it is necessary to do identification. If you consult an insurance company, don't consult an insurance company related to your case. It's best to consult an acquaintance.
If you plan to sue, it is necessary to identify it and go to a bigger hospital for review.
Signing an agreement is indeed a big problem, but it is not without the opportunity to reverse the case. As long as you have enough evidence to prove the seriousness of your father's injury and the collusion between the traffic police and the insurance company, you will have a chance to reverse the case. It may be difficult to obtain evidence in this process. If there is no evidence, the court will generally not support you.
I hope you can find a breakthrough.