What Tyler is saying is the Capoeira (backstep) pass isn't possible if you were playing lockdown. If your opponent was actually in lockdown, their leg would be too deep to complete the backstep.
The backstep/capoeria movement is only possible for the top guy if he's in your 1/4 guard.
Maybe I'm all wrong and I don't want to derail this topic but when you say "What are the options from there", I think that's a little like asking "What are the options from a mounted triangle" The options are you hold on for dear life and hope the timer runs out - in the same way - if someone back steps and hooks your leg - they're pretty much going to pass - at least that's what I think - you're going to have to wait for someone more experienced to jump in here though.
In terms of what you can do BEFORE this happens I have a few ideas. but I'm only a white belt so take everything I say with a pinch of salt.
As soon as someone passes your lockdown it won't be long before they donkey kick against your top leg and pass into side all together. My coach always tells us that you need to identify when you're losing the position. Concede that you've lost the position instead of trying to fight a losing battle and wasting energy - instead set up your next attack while the opponent is compelting their move.
Along this line of thought, some options I try and use are:
Mini Stomp:
I'm sure someone will correct me if I'm wrong but I remember Eddie saying something along the lines of "If you don't have a mini stomp game your lock down game is useless" So that's probably a good place to start. The best defence is a good offence so try and get used to getting someone back into a lockdown after they've passed into 1/4.
Quarter Shell:
By ensuring that you don't allow your opponent to get an underhook and a crossface, bear trapping their leg, you can do the stuff they show in Warm ups E
Dog Fight:
A massive path which can lead to you regarding, taking the back/into the truck, getting a triangle, getting a sweep, going to prison guard...
Those are three ideas, sorry if that doesn't answer your original Q though.