I think back to the book "Thunderbolt" about Robert Johnson. On two occasions, when his ship was damaged, his first thought was to bail. The 1st was when he was basically blasted from the sky but unbeknownst to him, it wasn't enough to bring down his P-47. The second was after that, in which his rudder was shot away. Both times he ended up staying in the plane. The 1st was because he couldn't bail out because the canopy was jammed. The second was once he gatherd his thoughts, after the initial shock of being hit, he realized his airplane was flyable.
Experience. At the point in time of the story, the Luftwaffe pilots were green, as already stated. These German flyers did not have that experience.
Also, as in any one side view of a story, we don't know what the German pilots were thinking or going through. The first that bailed had been hit. Only he knows what had just really happened to the plane. There could have been fire, flight control loss, injury to the pilot, anything that made him decide it was time to get out. The second is harder to explain, but I think it is just the mental attitude. Great leadership, great training, and confidence in yourself could overcome what the second pilot did. I probably would have pissed myself.....then bailed out.