I can quite clearly remember the the old CAR/ANR that made reference to 60 degree pitch up as a limit, it has since been removed. Abrupt changes of direction is somewhat subjective, is an Ag aircraft in the course of manouvering aerobatic? Never heard of anyone prosecuted for the pull up at the end of a spray run. Helicopters turning in short radius or on the spot abrubt? Doubt it.
Squawk 7700 I think you might have been misinformed, just because an instructor said it was so does not make it so. Old or young, instructors can still be wrong. As someone said a smooth pull up then gently into zero G is hardly aerobatic, unfortunate and somewhat suprising that this alone damaged engines, but I won't comment further as have not read the limitations section for that particular aircraft.