you can be pretty sure that the controller was very accurate
At 10:39:50 gived ATC distance 6 km. Acoustic signal of OM sounded betveen 50-58th second, middle is 10:39:54 and distance OM-THR is 6.26 km. The horn of OM sounded 4sec
after moment when ATCO was reporting 6km. It ought to sound 3.3sec
earlier.
I fully agree that a eventual radar inaccuracy was
not the reason of the crash. Your last sentence implies the reason.
In graphic: distance vs. time
Imageshack - smo00.png blue OM/MM, brown ATCO