Well, not only to cover themselves but also because reporters, especially TV reporters, aren't the sharpest pencil in the box. It was just an internet rumor that got reported as fact, like others out there, and has managed to perpetuate itself. No basis in reality, much like other internet "facts". :)
I've never turned our fridge off when refueling, but the TV is a diesel so we aren't at the gas pumps usually anyway.