Gordy - except the separation point is exactly where the MR blade would hit and the driveshaft has been chopped neatly at an angle as well.
Bob - not speculating as to why this sad accident happened just the cause of the TR boom lying away from the rest of the crash. The witness may well have seen the aircraft break up in mid-air - that's exactly what it would look like if the MR removed the tail section. As to why??? the crash investigators will figure that out. A pitch change horn failue could have the same result as low G, low Nr, mast bumping.