By making a few assumptions. The bloke was a proven overconfident person with exceptional demonstrated abilities. Most likely airframe icing brought the Plane down. . When you have ice the control, performance and stall speed change massively and the window can be obscured. I've had extreme icing in that area when NIL Icing was on the forecast. Extremely LUCKY to survive it in a DC 4. Had icing also West of Albury in a Mooney. Had to descend fast. to warmer air.. Nev