The FBI director is an appointed position. It appears that the prosecutors from the Justice Department are also appointees. All appointees are political, so I’m not sure what sort of distinction they are trying to draw, except perhaps that this reeks and they don’t want to damage Lynch’s career.
Years ago I knew the LEGAT in Rome. A career FBI, guy, he epitomized all that is good about the Bureau. He’s probably beside himself these days..
The lawyers working with the FBI from the DOJ are career employees. They are not appointed. Lynch has stated that several times.