I had originally spelled ‘backlead’ with a hyphen, but the hyphen look a little odd, so I deleted it. I decided against using two separate words to retain its sense as a single concept, hopefully reducing any confusion for anyone who was unfamiliar with what it was. I have since added the hyphen again, but I'm not sure how I feel about it. My goal was always to draw attention away from the idea that Squall 'couldn't dance' and toward the idea that they just weren't dancing well together, largely because Squall initially didn't want to.
I was a little concerned about using a term that might not be known to anyone who is not a dancer, but I felt that simply saying something like ‘lead’ was not nearly accurate enough. Leading can be understood in purely military terms, and it is usually considered a good thing. Back-leading is almost universally a bad thing, and it is a far more intimate faux pas. By using this term, Squall is accusing Rinoa of bad etiquette (while at the same time deflecting away any blame for poor performance on his part). Of course, this implies that Squall is well-educated enough to actually have a notion of what proper etiquette on the dance floor is. It also may imply either that Rinoa is not as well-educated, or that she is too presumptuous to care. In this way it helps to establish the dichotomy between their characters. Squall is rigid and duty-bound. Rinoa is wild and free.
More importantly, interpreting the dance within this context helps to frame the entire trajectory of their relationship. Rinoa begins by being impulsive and charismatic, but also clumsy and rude. Once it’s clear that things aren’t working, Squall begins to take initiative, accepts responsibility for the situation, and asserts his own leadership. Rinoa responds favorably to this, begins to follow his lead, and before you know it, sparks fly.
Though I am not convinced that the original writers did this intentionally, the vanilla story throughout disc 1 comes really close to following that same structure precisely, especially during the missions in Timber. By only changing a few key lines it’s possible to interpret the dance scene as a(n admittedly simplistic) foreshadow for their entire relationship.
Unfortunately, some of that nuance is lost if you only presume that Squall was criticizing her for trying to step up and lead him somewhere he didn't want to go. (And even more so if anyone thinks that Squall didn’t know how to dance at all, and he magically learned how in the course of one song due to Rinoa's incredible power of love and friendship.)