I don't know if there is a rule against it or not. I don't think they should be able to use the illegal technique for any reason. Now refs are getting on fighters for leading with their fingers out because of the potential of an eye poke. Why should a fake soccer kick be ok? For instance, in a Bisping fight, maybe Mayhem maybe Jorge, Bisping knew full well the guy was on two knees but he still threw a kick up over his head for some reason. I think it shouldn't be allowed. There's potential for the strike to land and also don't these guys train within the rules? Seems cheap to me.