Thoughts from pilots...

I'm curious to know what actual maneuvers he was doing, and how they know this. Aerobatic aircraft have a G-meter that keeps a memory. They probably have a GPS unit that shows some track info and maybe some vertical info, but GPS vertical info is only so accurate.

Eyewitness accounts can be only so useful, especially when most witnesses are only used to seeing planes fly by 6 miles high leaving puffy white lines.

2 G's is nothing in the aerobatic world, although it's close to the limit on regular airplanes. Also a low powered amphibious airplane could easily be stalled with a high G maneuver (pull up to a zoom climb) and it sounds like that's what happened, with not enough altitude to recover.

From the amount and type of drugs he had in his system, it seems to reason that he was an addict and that is sad- could have led to him making poor decisions.