well i dont bother to film which is why i havent mentioned it until someone else stated they were having the same issue. no sense in being the only person to talk about being effected by this if i didnt have the film that i knew someone would ask for to back it up. but when i saw that i was not the only one, and that it was someone like Silat says he is having the same issue then i felt it was worth listening to the bs about film, or lack thereof, to mention that i had expirienced the same issue.
my most specific circumstance was on tuesday night/wenesday morning. it was only me, a K4, and the enemy plane, a spit9, in the air and as i had found him just outside of his base i am very certain that there had been no one else to close enough to have caused him damage before i fought him. we engaged each other and began to do the do, he had me dead to rights i was so out classed and i knew it. he was turning under me as i went into a fish flop stall and would have the perfect profile shot on me within a turn. as bs luck would have it i flopped and there he was, i pulled the trigger and watched as a tater hit him in the canopy. boom, spit9 all gone.
now i was watching my screen to see the name of the defeated pilot so i could salute him and tell him that it was pure luck that beat him and not any skill that i possed but the kill never showed up.
when i made it back to my base and landed i went in the hanger and looked and i had recieved no points for the destruction of the spit9.
the other event could have been as you imply skuzzy, that someone else had done the killing damage to the enemy plane before i arrived, but in the above descibed encounter there was no one else, thus there could not have been anyone else to have damaged him prior to my arrival.
good luck in fixing the issue if there truly is one in the game and not just in our (the players) individual compueters/setups.