Germans actually were commendable administrators. In the final stages of the war the constant relocating of units eventually heralded the breakdown of the adminstrative system. It took weeks or months for award proposals to be answered to, victories were sometimes lost in the papermill. Even though a wreck was counted in the backyard.
Otto Schmidt,
Josef Jacobs and numerous other aces as well as lesser-scoring pilots claimed more planes than could be confirmed in these final days. The standards of confirmation hadn't changed: it was the rate with which it happened. It became increasingly difficult to get a claim confirmed. A wreck that was on German territory could be on Allied territory within one or two days. The system just could not keep up with it anymore and it resulted in (probably - I have no concrete proof) a lot of victories remaining unconfirmed. If you would check the last three months of the war in all the Jasta diaries you'd probably find victories that were verified by evidence but not by official confirmation. They were not counted in the victory total for a person, but they were recorded as destroyed.
The same thing happened to the administrative system during WWII. In 1945 the jets commanded the skies (when they managed to get airborne) but many pilots did not get their claims confirmed. Two reasons: the breakdown of the administrative system and the jet war not allowing kills to be followed down. Crude rockets were effective against bombers but it was almost impossible to discern who launched the rocket in the melee. Georg-Peter Eder claimed 36, 12 were confirmed. There were other men who outscored their confirmed jet-kills by a factor of at least 1 (Baer I believe).
Actually it is a bit of a repeat of WWI.
Kind regards.
Reinout