I completely agree with dpeters. Not getting credit of planes you shot down is painful (although it could be rather common for real pilots in WWI - I remember the Blue Max film, in which a fictional pilot spent a day looking for a plane he shot down and finally he wasn't credited for it). I could stand it if it was because no one else saw the plane going down. But it is a real immersion killer to see a plane bouncing over the ground as if it was on the Moon.
Unfortunately I don't have the knowledge to make any improvement on the issue. I can only make suggestions: did anyone played the old Red Baron II simulator? Of course IL-2 is MUCH better, but flying Red Baron you could experience an absolute feeling of weakness: a sharp turn could break your wings away (especially the low wings of older Nieuports). If you didn't want to hear your plane cracking you had to perform extremely gentle turns. I don't know if it was very realistic, but flying those planes was VERY SCARY.
Just as a suggestion to anyone who can do that: what about making WWI planes (especially the oldest ones) much weaker? Probably they would break down more easily when colliding to the ground. Probably it would be easier to shot down planes (at the moment sometimes it is really hard to shot down a plane, even using all your rounds on a single one). And finally, the feeling of helplessness in those beautiful but weak planes would make DOF a completely different experience to WAW and JTW. I think it could be in the spirit of CUP: one hundred years of flight evolution, and we have the luck to experience it!