I think the occasional statistical flucutation/fluke can happen to any armament. I don't think anyone considers the 30 mm on the 109K-4 to be underpowered in any way, but I remember in The Final Battle scenario landing two hits of 30 mm cannon from a 109K-4 on a P-51 (when usually one hit is plenty enough to kill one), and it flew away.

A little later in the same fight, I hit a different P-51 with 2 shells, one in the left wing and one on the tail:

and that behaved as normal -- each location being completely blown apart by the single shell:
