Although approved it’s kinda dumb not to have another deck officer in that craft, too much going on for one person IMHO.
I’ve wondering since Sunday, “what was the OAT the last time the pilot set the altimeter before Sunday,... 70... 75? And what was it in the overcast mid-morning air,.. 55... 60? Did he forget to set it before flying that day? Would that have been the difference in clearing the top of the mountain in the fog?”
Over 35 yrs ago my dad flew a Cessna Conquest twin turbine for a business, single pilot, in all sorts of conditions. But, by that time, he probably had 6 or 7k hrs in twin Cessnas. He always said the best compliment of his flying skills came from the future CEO of Hardees, Jack Laughery, about 1974: “Ben doesn’t get in an airplane to fly it. He puts it on like a sport coat, and just wears it.”
As I’m sure you are aware, hours aloft as PIC is only one measurement of skills. Some folks get the ratings, and experience, but are still scary to watch fly an aircraft, because it just never becomes natural to them.