Following a midair collision, a passenger in one of the planes, a citizen of State A, sued the Federal Aviation Administration in federal court under the Federal Tort Claims Act, alleging negligence on the part of its air traffic controllers. The passenger also named the pilot of the other plane, a citizen of State A, as a defendant for a claim based on state law negligence. The pilot moves for dismissal as to him. If the court grants the motion to dismiss, what is the most likely reason?