He told me that they had been instructed to dive over the boom... which apparently was somewhat more sensible in the abstract than when a ME-109 was trying to shoot your ass off.
I did read an account of a B-17 ball turret gunner. The aircraft was in trouble, ammo boxes on fire, and a waist gunner panicked, jumped out the side, splattering himself on the stabilizer.
So it just wasn't boom aircraft.