Michel
First an apology. Don't know why I wrote NAGr 8. Was supposed to be NAGr 5 all the time. The reason Gerhard Frenzel is quoted in my book was that he fled to Sweden at the end of the war and told his interrogators he was the one.
All shoot downs are intentional in war. The knowledge however what you are shooting at may not however always live up to our expectations. Aircraft recognition was generally of a rather low quality, on all sides. You basically saw what you expected/wished to see. Also remember the old saying, the one who shoots first usually live to see another day.
Don't forget the number of blue-on-blue incidents during WW 2 was rather staggering as well, which says a lot why so many individuals completely failed to see any national markings (and, added to that failed with their aircraft identification).
Peter
It seems new information/research has produced a different result regarding the shoot down on 14 May 1944. Will read it through. Thanks for pointing it out!
Cheers
Stig