Hi Michel,
I don't think anyone here was stating that the information here is for absolute certain. The MACR clearly states they were having a running battle with aircraft identified as Focke Wulfs. If memory serves, the best source for the Lennart claim would be Boehme's old JG 7 book, and I don't claim that it's anything other than authoritative for its time...
http://www.303rdbg.com/MACR/08170.pdf
https://catalog.archives.gov/id/91048539