Also in the article it was written:
"Ushiro Sensei taught how he harmonizes with his opponent, which, on the surface at least, seemed quite different from how harmonization is thought of in aikido. "
Interesting choice of words (underlined). What one might discern as different methods of instruction, but equally suitable for unhealthy ego-attachment. My teacher swore once he only ever knew two techniques in aikido -- irimi and tenkan. I've whittlin' mine down ever since.