As there was no other Stuka-/Schlachtgeschwader with Ju87 around (except the Romanians), I am very sure that it must have been SG2.
70 losses of 100%? Where is that data from?
I can find ca. 20 for example when checking the links at the bottom of this site:
http://www.ww2.dk/air/attack/sg2.htm
But anyway: Maybe soemthing is confused (in the story or in my memory) and the gunner survived (with the pilot dying). What "pilot only" loss do you know?