Yes, the clause that the settlement is a compromise and that this is a "doubtful and disputed claim" is typically in an auto insurance settlement agreement. This is a way that an auto insurance company tries to minimize their risk and liability. So the insurance carrier is basically settling with you but without admitting liability.

Many auto insurance settlements also have a "hold harmless" clause. This is basic terms means that when you sign the release, the claim is over once and for all. In the hold harmless clause, the company is saying that should you initiate legal action against them or their policy holder (after signing the release) you will be responsible for any legal fees that they incur defending your legal action.

This type of clause is there to prevent you from changing your mind at a later date and trying to get more money. This way if you change your mind and cause the insurer or policyholder to incur defense expenses they have the right to sue you to get paid back the defense costs.

Usually a release will also note that this settlement is not an admission of liability. That is standard language. Many releases will typically have a doubtful and disputed clause as a way in which to say neither the insurer nor policyholder is admitting guilt.

General releases for insurance claims can state that the person being settled with waives and assume the risk of any and all claims for damages which exist as of this date or do not know or suspect to exist, whether through ignorance, oversight, error, negligence, or otherwise. The doubtful and disputed claim clause may also say something to the affect that you have accepted payment of the sums specified as a complete compromise of matters involving disputed issues of law and fact. A settlement agreement may then go on to say that it is understood and agreed to by the parties that this settlement is a compromise of a doubtful and disputed claim, and the payments are not to be construed as an admission of liability and in fact liability is expressly denied.

Insurance settlement documents usually will have a lot of legalese in them which try to cover any situation that may arise. The insurance providers cover themselves by stating something such as the policyholder and their insurer are released from any and all actions, causes of action, claims, demands, damages, costs, loss of services, expenses and compensation...any and all known and unknown personal injuries, damages and losses” resulting from the automobile accident.

If you find anything unusual about the settlement release given to you by the insurance company of the at-fault person you can have it reviewed by a lawyer. If you do not want to pay for legal help then you may also try contacting your state's insurance regulatory body for consumer help and advice.