I suspect there is a little more to the story. On the LiveATC audio, he was giving descent rates and asking tower/approach for headings. Didn't speak like a pilot but seemed to know more than a layperson. Maybe some aviation exposure but no flight time? Whatever the case, very well done by both him and ATC.
I think that's true as you stated it, but this wasn't a little 150; it was a 208 (which seats up to 14). Very common to have non-aviation passengers in something like that. On the flip side, the fact that he was sitting front-right seat could be evidence he had some aviation background (e.g. as a pilot + aviation enthusiast, I would excitedly take that seat if it was an option).
If I kicked off in flight on day/good weather, and she was up front, I’m pretty sure that airplane would end up inside the airport perimeter, probably stopped on all three wheels on a runway. That’s not to take anything away from this pax feat, but it’s pretty likely they at least had a pretty good idea of how things work. (And were in a fairly simple airplane.)