More telling is the report of heavy fog. I'm surprised they aircraft was cleared for takeoff under those conditions. As a VFR pilot, I recall the minimum acceptable being around 3,000 ft AGL. "Scud running" i.e. dodging clouds was considered poor practice. The FAA regularly sent a newsletter detailing accidents and their causes.
The minimums for takeoff are much lower than for landing. Basically all you have to do is track straight and liftoff. They probably would have been out of the fog very quickly after take-off. I suspect maybe one engine went out, or the pilot got disoriented.
I have an IFR rating. Even after all that training I still didn’t want to do actual IFR by myself. With foggles or a hood you can always cheat a little, you can’t when its the real thing. None of my training took me into actual IFR.