It's all bull anyway, G2, the effect of pitch on point of impact. Don't pay any attention.
There are, according to Major-General Hatcher, two phases of recoil.
1. Phase 1, the rotation of the gun around its center of gravity. This is independent of pitch, since it is something else entirely, controlled by different forces.
2. Phase 2, the building of force on the shoulder, happens much later. The gun has only moved back a third of an inch when the shot exits and the force on the shoulder in minimal, since you can compress your own shoulder that much without even trying and without using much force at all.
So by the time the force on the shoulder peaks the shot is already at the bird and long, long free of any magical pitch effect on POI.
It's just gun club talk.
What's wrong with where the gun ends up now? Sure, it's way over the bird, but with your point of impact you shoot when the barrel is well under it, so anything that happens now is just where it ends up, that's all.
Neil