There is an old saying about shooting/hanging/killing the messenger. In the USSR, Stalin was known to kill people who annoyed him, never mind people who told him he was losing a lot of ariplanes and troops to the Germans whenhe wanted to win. The Commisars weren't highly motivated to send in accurate numbers. They were motivated to do whatever was reuired to keep Stalin happy or at least focused on someone else.
Some of the same happened in Germany, according to former German soldiers I have spoken with over decades past.
Many times, a damaged plane didn't return to the home airfield but rather landed at another field. In the chaos of wartime, the two reports, when it DID return, were not likely reconciled accurately every time. Since they WERE two reports, it would have been EASY to file them is separate places or lose one. In some cases a returned plane was scrapped, but classified as returned in the mission action reports. In others. a plane was classied as "struck off charge," but was later repaired with parts from other aircraft and flew again.
From personal experience, loss reports are not nearly as accurate as people tapping on computer keys today seem to believe they are.
I have told this story a couple of times in here, but I was charged with coming up with a database for tracking US Navy Standard Missile parts for a company in Scottsdale, Arizona as a young engineer. I did, and we had about 2 dozen parts that were classifed as missing by virtue of having been "expended in test." Amaxingly. several shpwed up as customer returns from Australia for repair! Turned out that when inverntory time came around, the clerks in the Navy were told to account for all parts. If they couldn't find them, they listed them as "expended in test" when, in fact, they were sold to Australia as Fopreign Military Slaes (FMS). That's only ONE time. There were others, amounting to several percent that were classifed as one thing and later found to be another when they either "showed up" or could not later be found.
There was a case when a Navy base on the west coast got a nerw commander and he decided to ":clean up the base." There was an old railroad siding just OUTSIDE the base where two old rusty railraod boxcars were standaing and had been for years. When they cut them open, there were 10 SM-2 missiles in shipping container that were there, outside the base, and could have been stolen. In the database, the serial numbers were shown as "expended in test."
Don't tell me inaccuracies don;t happen!
I have put most of the tables from the Statistical Digest of World War Two into Microsoft Excel. There are at least 10 tables where the totals shown simply don't add up. That is, I put in the data as shown in the tables (checked multiple times) and them used Excel formulas to sum them up, and found several places (more than you'd think) where the published totals don't tally correctly. There are two possible explanations. One, the toals are correct and the data are wrong, and two: the data are correct and they added up the data manually wrong. Of the two, the second is WAY more likely. It;s hard to get an accurate total if the data you are using is incorrect.
In point of fact, there is no objective evidence that the data are correct at all ... only our assumption that is must be. To have objective evidence, we'd need a separate total known to be accurate. We don't have that. We only have what we have, and we assume it is close enough to be nearly accurate. In many cases, it likely is. It is also likely thath in many cases, it isn't. The fog was war doesn't only apply to combat reports. It also applies to data collection and records that we have no way to determine as actually complete.
Lots of wiggle room for inaccurate data, and I have seen actual records lost (and also discovered that were formerly presumed to have been lost) in the 1970s peacetime UJSAF. There was MUCH more opportunity for inaccuracies to creep in during WWII when records were on paper that sometimes got lost, wet and stuck together, or had the ink run and become unreadable, and also disappeared on ships coming home during the war. Reconstructed data is often at odds with what really happened.