The Sheriff reported portions of the left wing, approx six feet of the right wing, and the horizontal stab were all found a good distance from the fuselage.
Don't know if the acft had wx radar, or what sort of anti/de-ice gear was installed - boots perhaps. Also don't know his quals or currency.
He could have penetrated a cell, he could have iced up, he could have failed to turn on pitot heat (as another poster mentioned) or it failed, or he could have taken a lightning strike that knocked out the A/P and electrically powered instruments - all while in IMC. A lot for anybody to deal with. Could be a bit like Air France 447 over the Atlantic.