They haven’t since there is no proof.
And I know people like you are working overtime to find any tangible link but since you havent that means that Xe or DynaCorp are there to guard diplomats since Pakistan is a dangerous country for foreigners.
As for terrorists killing Zero people and still being considered a terrorist. If we apply that logic to Muslims, then all Muslims can be considered terrorists by people in the west.
Develop some rational thought before you jump into an argument.