Really we don't know how energy bending used to work. Only that it's what people used to bend before they bent the elements. To me that means there could be varying degrees of energy bending. I don't see why it couldn't actually be energy bending, just some technique different from what Aang used.
--
~Ç~ http://img.imgcake.com/AlecTrevylan006/fdshieldpngyn.png Eff_Dee
http://img.imgcake.com/nio/9fdpngys.png