Legal Question in Personal Injury in Indiana

yes

It's certainly possible. If someone sues you for an auto collision, after you have already reached an agreement with that person resolving the matter, then you need to show the court that you and the other driver have an agreement. It will be your burden to convince the court that such an agreement exists.

Obviously, if there is a written, signed document supporting your claim of settlement, you should show that to the court. If you do, the court may grant you a judgment, and deny the other driver's claim, without a trial. Courts in Indiana have a policy that written agreements are usually enforced as written, absent evidence of fraud or similar problems.

Without a written agreement, you must prove that there was an oral agreement that is an enforceable contract (that there was an offer of settlement, acceptance of the offer, and that the agreement was performed as agreed). If you and the other driver disagree about whether or not there was an enforceable agreement, then the court may very well decide that a jury needs to evaluate both your settlement claim, and the other driver's claim that he/she was injured and deserves compensation.