CSI: "class four rating"?!

In a CSI Miami episode that I recorded awhile ago, a pilot crashes
onto a beach. The NTSB inspector (who appears to be a complete
idiot compared to the profound star of the show), says "long flight
over the ocean; the pilot probably had a class four rating".

Does that have any basis in reality? Or is it right up there with
a pilot's preflight check missing explosives around a huge valve on
the bottom of the fuselage?

I haven't been able to bring myself to finish the episode. I'm
sure there's more wisdom.

--kyler