I made a small scenario to test it and it turns out this is the result of a retreat hit on an already retreating enemy. There are kills there.
However the 4kills 16 pins 10retreats seems like 1-3-2 pattern type used by arty usually. I was probably just unlucky several times before and got no kills at all and everybody retreated on time. (Note that pak guns are usually not that numerous, and i never knew their purpose is to suppress and pin).
This pattern is just hilarious. It is funny to score 40 hits with paks75 on trucks and greyhounds, kill 0 and force them to retreat :-). (well on my last test at least i got 4/30).
It seems this pattern is given to all paks(except the 88mm,122mm paks), flak, pioneers, ss pioneers, staff and poor infantry and antitank; but not to panzergrens, jager tanks, brumbar; which makes the first terribly bad in combat compared to the latest.
Also almost all arty but the 122mm_R and 152mm_R (it is the ArtCode1,2,3 right?).
I think something is messed.
I can send you the scenario but i need an email