A 'pebble' falling from several kilometers (without any acceleration except for gravity) will kill you I think. At least that's what I remember my calculation of over a decade ago.
Did you account for air drag, or did you only consider gravitational acceleration?
At that time it would have lost all of its rotation and probably would be just tumbling with added air drag. A parabolic shoot on the other hand.... But still most probably not deadly... if it was so unfortunate to hit someone in the head/eyes/neck. Which is like an extremely small probability in itself. A hit to the body of person with clothes would probably just bounce (not without some moderate impact pain depending on clothes thickness) and not penetrate.