"According to the official Air Ministry File into the incident (File AIR 81/628): "Blenheim N6192 assumed lost at sea off the coast of France, 27 May 1940. Sergeant J Mahoney, Sergeant W C H Paish and Sergeant H Warman: missing presumed dead".
Bill Chorley himself recognised that each volume of his Bomber Command series wasn't definitive or perfect, and helpfully provided pages of amendments in subsequent volumes.
I've worked as far as the corrections list in the 1945-47 volume, correcting by hand entries in the preceding books. Many pages are now covered in alterations. There are even corrections of corrections!
Bill Chorley was obviously doing the best he could with the material to hand at the time. His books were undoubtedly a huge aid to air force historians. This is not a criticism.
But beware: don't quote from or refer to the Bomber Command volumes without checking later ones for adjustments.
Also be aware also that the Aviation Safety Network website tends to rely on secondary sources (eg Jim Halley's RAF serials books).