You can't determine what shot down a aircraft from pieces of a aircraft, or smoking holes in the ground, I call BS on that Dave.
What % of aircraft downed came down intact enough to determine what shot it down ?
Surviving crew would usually know what brought them down. Flak crews would sometimes be able to id the type of aircraft they were shooting at, and see the results of their shooting soon enough to make a claim.
Nightfighters usually could id ( but not always) the type of AC they were shooting down, and would know the general area of where they fell.
A for instance, you've got a lot of intact crashed Landcasters but a lot of them will be burnt out hulks, and you're going to have a lot of just Landcaster parts in a general area, and then you've got the smoking holes. You've got a lot of claims, do you really believe they had a 3rd Reicht's equvilent of crash scene investigators with the time to sort this mess out. Now days individual crash investigations usually take months, but the aryan supermen could do it in hours of course.