When employed in an at-will employment state, does an employee terminated for cause have any recourse if there has been a precedent set that allows

The exceptions to the "at will" rule are narrow, because the public policy that underlies the rule is to encourage both employers and employees to form relationships as they deem economically appropriate for them; a court will usually not substitute its judgment for that of an employer in determining whom the employer should fire or retain. As a general matter, a practice or policy of an employer will not provide an exception to the "at will" rule unless it is essentially contractual in nature, such as contained in an employee handbook or published in a policy manual. The mere fact that the employer chooses to ignore misconduct from another employee would generally not rise to this level.