Maybe a dumb question, and I never saw the photo, but how does a wing spar that failed in flight look different from one that failed on impact?
IF the pilot did break up attempting an aileron roll my guess is that it wasn't from pulling too hard, but too little. Some combination of too high an entry speed, not high enough pitch on entry, or leaving the power in too long... resulting in exceeding Vne in the recovery. I have botched enough aileron rolls in Citabrias and Aerobats to know how fast they can pick up speed if you get things wrong and a C210 with gear retracted would get away from you a whole lot faster. I don't know how that would look on indigosat, but I guess no matter what happened at some point it would show an increase in speed and loss of altitude.
Maybe the poor guy was just unlucky, seems like there isn't enough information to know what happened for sure and there probably never will be.