[Laurent Rizzotti]

I guess you're interested in identifying the German bomber shot down.

The War Diary of USS Menge for April 1944 is available on fold3, but the names of the two prisoners is not given. Only info is:

20 April 1944, 2140 hrs: took aboard 2 slightly wounded German fliers who were immediately given first aid and put under guard.

21 April 1944, 0732 hrs: moored at Mole 46, Algiers, where the survivors and prisoners were landed
(note: Menges rescued 137 survivors from the sunk destroyer Lansdale)

By the way the Menges did not claim the bomber shot down, other ships did.

If you have a fold3 accound, there is a 58 pages report about this attack, in the WWII War Diaries section:
COMTASKFOR-66 › Rep of Air Attack on Convoy UGS-38, Off North African Coast, 4/20/44

By the way, here is what is written in "Sea Eagles 2: Luftwaffe Anti-Shippin Units 1942-1945", page 171:
"The attack on convoys 'Whoopee' and 'Donaghue' on the night of 20 April 1944 were more successful for the Luftwaffe: a troopship, two freighters and a destroyer were sunk and two freighters damaged, but four Ju 88s from I. and III./KG 77, one Ju 88 from III./KG 26 and two Do 217s from 6./KG 100 were shot down, one from the latter unit being commanded by the Staffel kapitän, Hptm Will Scholl. The escort from I. and III./ZG 1 also lost four aircraft, including that of the Staffel Kapitän of 7./ZG 1, Oblt Marin Reuter."

The convoy Whoope was the UGS 38, that lost the Henry Hamilton and Lansdale sunk, and 3 freighters damaged, one sinking the next day in tow. The convoy 'Donaghue' was probably a small convoy sailing from Corsica to Algiers, and probably 100% French. It seems that it was confused as their target (UGS 38) by many German crews, and the liner "El Biar" was sunk. IIRC the escort of the small convoy claimed more aircraft shot down by AA than the UGS 38 (that claimed 2 shot down and several damaged).