[Peter Cornwell]

The Lw GQM Returns (Abt.6) do record the loss of a Ju88 of II/KG51 and a He111 of III./KG51 on 1 June 1940 the first supposedly landing in Italian territory while the second was reported shot down over the French-Swiss frontier. As you say, the first was as follows:

4./KG51 Junkers Ju88A-1 (8004). Engaged over Lac de Paladru by Adj Baritel of GC III/9 during sortie to Marseille and pursued north-east eventually forced-landing near Ruffieux, east of Culoz, with port engine feathered 1.45 p.m. Possibly that also attacked by S/Lt Kalpas of DAT Lyons. FF Fw Reinhold Müller, BF Uffz Paul Dickhut, BO Gefr Bernhard Sartor, and BS Gefr Hermann Spieß all captured unhurt – later released. Aircraft 9K+DM 100% write-off.

However, the NVMs for II./KG51 only record the loss of one crew on that day and I have found no other evidence to support the second entry which I suspect to be erroneous.