True. The Luftwaffe's claim procedure was very strict, but there were hits and misses as it were.
The Luftwaffe's beuracratic procedures were involved,; that's not the same thing as being strict.
For a claim to be confirmed required a minimum of one witness, often the claimants wingman.
At some stages of the war, other methods of confirmation were combined, such as looking for wreckage, confirmation of ground observers etc.
The reputation of the Luftwaffe procedure as being strict probably stems from the fact the Luftwaffe spent much of the war on the defensive, and indeed as far as the Americans are concerned, almost all their battles against the Luftwaffe were over German held territory, with fairly stable lines, which afforded the Luftwaffe ideal conditions for verifying claims.
However regarding Claims during the BoB. The Luftwaffe did indeed over claim, but were those claims actually awarded for the most part? Pilots may have come back claiming they shot down two Spitfires, but how far did it go? I don't know.
The Jagdwaffe made about 2000 claims of single engined fighters, as against British losses of half that to all causes. That's a roughly 3 for 1 overclaim.
There's two ways of looking at that.
One is that these were claims only, and not confirmed.
You can take that line because so much of the Luftwaffe archives were destroyed, it's hard to find "final" decisions over kills.
However, looking at the "claims", and comparing them with the well known Luftwaffe aces's totals, you can see that almost all the "claims" are counted in those totals.
For example, the claims list covering the period 1939 - 41, West Front and Poland, shows Galland making 100 "claims", 5 of which were definately denied. Galland is usually credited with 97 claims during this period, however.
Molders made 69 "claims" during the same period, Molders is usually acknowledged with 68 of those.
The same sort of ratio is true for all the aces I tried, almost every single kill is counted towards their acknowledged totals.
The other way of looking at it is that those victories were not confirmed by the Luftwaffe, but in that case it means that the high scoring German aces, of that period at least, did not have very high numbers of "confirmed" victories, but only high numbers of claims.
In short, if Galland really had 104 confirmed kills during the war, the Luftwaffe awarded 3 times the number of kills during the BoB that were actually achieved, or
If the Luftwaffe did not confirm those claims, Galland did not have 104 kills, but 104 unconfirmed claims.
OKL did approach Hitler with wild claims of 30 aircraft destroyed in the air on the 13th August, but those numbers were rapidly revised, when interrogations of pilots began showing up claims as probable's rather than actual "kills".
The claims list shows 29 kills that are nopt definately denied, but we can't be certain they were definately awarded either. The above still holds true, either these claims were awarded, or the Luftwaffe aces from the period each have X number of unconfirmed claims, not confirmed victories.
As regards defensive claiming, this is subject to error too. The RAF overclaimed absurd numbers during that Battle of Britain and they were let stand, even though Fighter Command knew it was bollox. It was done for obvious morale reasons and probably did do a lot to buck up the men.
The RAF claims are actually not that far off, as far as historical results go. They confirmed around 2500 kills by all forces, including flak, for actual German losses of around 1700 - 1800 to all causes on operations.
That's for confirmed kills, there were much larger numbers of "probables" and "damaged".