I didn't see this "stunlock," but ... ground infinites, whether or not they're escapable, have always been considered bad manners. i.e. Siegs don't AAAS dS repeat, Tias don't AA dS repeat, Dainns don't AA auto repeat (all of the aforementioned, at a wall/corner). I can't confirm or deny Biki A-spam's effectiveness, but what makes it acceptable in serious matches?
"It is not a disgrace to fail. Failing is one of the greatest arts in the world," however --
"Believe and act as if it is impossible to fail." ~ Charles Kettering