Someone wrote this on another forum. I think it is a very sensible view.
Having a fair degree of experience in aerobatics, I'll offer the following:
For control failure to be the problem, it had to be both elevator and aileron failures. The gradual pitch up and following barrel roll was actually fairly leisurely and allowed plenty of time at the top to either push to sustain inverted flight or roll back to upright. The pilot did neither.
The pilot is not visible in the posted photos. This is possible only if he has slumped hard forward or down and to the side. Given the restraining harnesses, both would be difficult.
Again from the posted videos, there is no evidence of a sudden pitch up, spin, snap roll, or any other heavy gee-load inducing maneuver. There is a noticeable pitch up, but it is not a "snap" type pitch. It was simply the beginning of a barrel roll that ended vertical in front of the stands. I saw no evidence of last-minute maneuvering, either.
Having said all that, video can be extremely deceiving. I was scored on several maneuvers that should have been zeroed because the video did not show what about half of the judges saw. The only thing less reliable than video is the human eye.
Let the NTSB do their work. Conjecture is painful for those closest to the event
I'm trying to read between the lines of that opinion--what that poster is pointing to, but not saying outright, and what I'm reading is that the pilot was incapacitated, which was cause, not effect.
Or am I misreading?