Agree with the Beagle.
Also-if this happened in the air when the test was terminated then the abuse/threat is directed against the commander of the aircraft - however insignificant that aircraft might be.
A radio call the airfield, flight school etc to have the police waiting wold have had interesting results for future licence attempts.
It does raise the little question as to when the behaviour was first demonstrated and so perhaps why did they get airborne in the first place.