Very easy to get into big trouble with a high performance turbo prop like that. The wing configuration does not lend itself to errors at marginal airspeeds such as landing. Recovering from such stall at low altitude may not be possible. A moments inattention and it stalls. These planes may be nicknamed “banker killers” just like Bonanzas are “Doctor killers”.
I believe there may have been severe icing conditions, at altitude, at the time, though no mention of it.