In broad terms, a documented history of warnings, efforts to coach the employee, and continuing problems will help defeat a wrongful termination claim. But any such claim is going to depend upon the facts of a case, including whether or not there is an employment contract that modifies at-will employment, and whether the employee has any colorable basis to allege violation of civil rights laws or public policy in relation to the termination.

If this is truly a concern, the employe should discuss the facts with its business lawyer and get some advice as to how to avoid liability. Even when employers aren't particularly concerned about litigation, they will often offer a severance package in exchange for a release of claims and, if the employer chooses that option, the employer can help them prepare an appropriate severance agreement.