Dunno, but I think it has to do with the side of the road you ride on in the states...
You lead a trackstand with the left foot because your on the right side of the road, normally with a slope going down to your right. So, it makes sense to turn your wheel to the left, and leading with the left foot.
While in the UK, it's opposite, so I lead with my right foot, turning the wheel to the right with the normal slope. I'm also right handed and use my right foot to skid, like you.
I'm kinda worried that eventually, all this right footed dominance might make my left redundent.