Hello Paul,
I've written an in-depth account of this raid in my new Nachtjagd Combat Archive series with Wingleader:
https://www.wingleader.co.uk/series/...combat-archive
but was unable to match the loss of BK779 to any known German Nachtjagd or Flak claim. Do you perhaps have any additional info on the time & place of the encounters with Flak over Berlin and then the night fighter?
Cheers, Theo