A question on Hans-Joachim Marseille's Battle of Britain period claims

[Juha]

Already at the turn of the millennium I saw the following table:
MARSEILLE - Battle of Britain
# Date Time Claim Local Obs
1. 20.08.40 or 24.08.40-- Spitfire (I have seen both dates as the Marseille's first claim, 24.8.40 seems to be more common.)
2. 02.09.40 -- Spitfire
3. 11.09.40 17:05 Spitfire
4. 15.09.40 -- Hurricane I
5. 18.09.40 [10:40] Spitfire (The time is sometimes given sometimes not.)
6. 27.09.40 -- Hurricane I
7. 28.09.40 -- Spitfire

What sources is this based on? The most surprising thing is that at Tony Wood's LW claims list and in Prien et al. Die Jagdfliegerverbände der Deutschen Luftwaffe 1934 bis 1945 Teil 4/II the only claim by Marseille with known date is on 08.09.40 Fhr. Hans-Joachim Marseille: - 1.(J)/LG 2 Spitfire �� - 09.40 plus info that I Gruppe (Jagd)/LG 2: period 26.06.40-31.10.40. Dates for various claims are not clearly submitted during this period in time. Obfhr. Marseille claimed 6, Ofw. Helmut Goedert claimed 4, Ofw. Hermann Guhl claimed 1 or 2 or Between 26/06/40 and 31/10/40, six or seven "abschuss" were claimed,the precise dates of which are not known,to which must be added five whoses dates are known but not the claimants.
On these 11 or 12 "abschuss":
6 by Marseille
4 by Helmut Geodert
1 or 2 by Hermann Guhl

I can easily understand that new information is found but why is the only former "for certain" known claim discarded?

TIA
Juha