There seems to be a habit in this game of immediately questioning any successful gun shot from the front quarter, which vexes me greatly, since any number of tight maneuvers can produce this situation- snapshots in a tight scissors, for example. I thought the reason HO's were found to be annoying and generally "un-sportsmanlike" is because newbies love to go for it in the merge, resulting in either a brief jousting match or a collision, which usually sends both pilots back to the field and wastes ten minutes for re-planing and transit time for no gain or purpose.
EDIT: My point being, of course, that pilots who are attempting to have a real fight instead of the suicidal head-on jousting match are justified in taking any shot they can get. If I'm running BnZ on somebody who can hang on the prop and has a cannon with a long reach (109F, say, with the MG/151,) and he puts his nose on me every time I dive in, then he's Doing It Right. He's obeying the Dicta, after all.