Anyway .. .. back to the more serious stuff.
Just as you thought IO540
The KFC225 has been a thoroughly unreliable product, failing a number of times in both pitch and roll. The roll failures have all been caused by the roll servo. The pitch failures have been caused by faults in the computer unit, or by the pitch servo.
I reckon it was not pulling the nose up enough before deflecting the ailerons.
oh, and why we were on the serious stuff, the little matter of an auto throttle might prove a problem, unless you are reckoning on maintaining full throttle over the top of the hammerhead.
and yes, Bob's other trick was to eat bickies at the same time as presumably keeping an eye on the tea on the glare panel, so you can have tea, bickies and no autopilot while still rolling, until you post it on Youtube and the b**st*rds want a meeting with you without the tea or bickies.