I understood a victory was only awarded if the a/c was shot down.
The Germans used a points system for the awarding of decorations and promotions.
In effect only on the Western Front:
Aircraft Type AbschussDestroyed - Herrausschuss Separation - Entgültige Vernichtung Final Destruction
Single-engined 1 - 0 - 0
Twin-engined bomber 2 - 1 - 1/2
Four-engined bomber 3 - 2 - 1
http://www.xs4all.nl/~rhorta/jgscor.htm