LOMCEVAK:
It is permissible to commence an aerobatic manoeuvre from what is technically a 'flypast' from the minimum DA height for flypasts so long as the manoeuvre is not technically 'aerobatic' until passing the DA aerobatic minimum. Therefore, pulling up for a looping manoeuvre from straight and level at 200 ft agl would have been within the regulations so long as the pitch attitude was such that it would not have been considered 'aerobatic' before climbing through 500 ft agl. There are many definitions of what constitutes an aerobatic manoeuvre but in general 60 deg of pitch is probably the most restrictive.
Thank you for the thoughtful rebuttal. I'm not an expert on aerobatics, though I have a lot of training and experience in safety, quality, and process control.
If I understand you correctly, a display pilot wishing to avoid busting the minimums would have to simultaneously monitor his changing altitude and pitch while commencing a maneuver, as opposed to simply starting the maneuver from a safe altitude and airspeed. Similarly, the Flying Display Director would need a protractor and some elaborate mechanism to determine if the minimums had been busted. And technically, a loop doesn't include the entry or the crucial exit, where the pitch is less than 60 degrees. (Odd. The entry and exit are scored for levelness in aerobatic competitions.)
May I say if true, that's insane?
Also, if I understand you correctly, it was permissible to cross that highway at 100 feet AGL. Silly me, I thought a "flypast" referred to flying along the runway, safely within the confines of the airfield. Crossing a highway at 100 feet AGL is also insane from a safety perspective.
I wondered how a terrible tragedy like this could happen. Say no more, I've got it down to a one word explanation.