Idiot Navigator!
Q1.) How could he figure out when exactly they're over the target when he repeatedly keeps looking up while talking (wayyyyy too much!) in flight?
Q2.) Why isn't he (instead of the pilot) steering the plane via the Norden bombsight's autopilot mode as they approach the target area?
Q3.) Why is the pilot telling him exactly when to drop the bombs instead of deciding himself?
You're gonna need a bigger boat.