Martin,
there was not so big German close formation of fighters in the air. The hostile aircraft were recognized as Wellingtons. The timing of victories, sure, there could be some inaccuracies, mistakes etc - maybe 3-4.
But I count some 11-13 (!!!) confirmed victories achieved apparently against the "ghost formation". On the other hand between 14.45-15.06 there wasn`t so much more to shoot down from the Helgoland formation. And at the time these bombers were far, far away from German Bight. They couldn`t stay for 45 minutes at Wangerooge or Borkum, right?
Maybe something wasn`t documented or even deleted after the battle ?
Regards,