It had something to do with the bomb release. On the dive the pilot would be fine but they found in testing that the pilot was subjected to 6G when he pulled out of the dive which resulted in blackout. They invented the auto-dive-recovery which deployed when the bomb was released so the pilot could black out or grey veil without risk of crashing. It was marginal because an object moving at 600kph only 450m from the ground in a 90 degree dive hits the ground pretty quickly if not recovered at the precise moment.

Imagine being the blake to test this out for the first time!