that is plain bullshit.
direction doesn't turn, if your backside on a rail, you're backside on a rail. the only thing you have to have in mind, maybe the fact, that a fakie ollie backside boardslide is a halfcab boardslide or if you don't do a halfcab its a fakie ollie switch fs boardslide...
i guess i have to make a litte video to show what what board-/lipslide is called...
a fakie ollie is a switch nollie and a nollie is a switch fakie ollie