Hi,
The only relevant
Luftwaffe victory claims for B-17s that I could find were:
- B-17 shot down near
Aubigné, north of Rennes, at 12:00 by the 9.
Staffel of
Jagdgeschwader 2, flying FW 190s (370 km from Bordeaux)
- B-17 shot down shot down at
Lac Hourtin at 11:07 by the 3.
Staffel of
Zerstörergeschwader 1, flying Ju 88s (50 km from Bordeaux)
So it seems that your father's aircraft was downed by 3./Z.G. 1.
Cheers,
Andrew A.
Air War Publications -
www.airwarpublications.com