The previous two techniques dealt with countering a single leg-like position when your opponent was seated. If his head was to the outside, you attacked his back. If his head was to the inside, you executed a back step pass. If we reorient the position to where your opponent is standing, attempting to finish a single leg takedown, your options are similar. Head outside: take the back. Head inside: back step. In the animations below, you can see that I take the back with an arm drag. As for the outside option, I personally tend to try and fight my way into a sprawl because a standing scissor leg takedown (the standing equivalent of a back step pass) is a bit too dynamic for my limited coordination.