Perspective,
Yep, or a stroke or some other issue. It happens on the roads and can happen in the air. It may well be a rare event but it could happen.
If bits fell off, I can imagine powered up and control stick pushed over in a medical event, an RV6 will be through VNE in a flash and beyond, and bits would then be likely to depart. If in fact they did.
Post-mortem might reveal something if this is the case. I hope the ATSB find something conclusive.