This abusive incident highlights China's aggressive foreign policy and is consistent with previous behavior by PRC diplomats in recent years. The move, clearly a deliberate provocation to teach protesters "a lesson," is behavior that seems in line with Xi Jinping's vision for his unprecedented third term. Such aggressive and authoritarian behavior is not acceptable in a rules-based order.
Hong Kong has long been part of China, and those who believe in its independence must admit the fact that it's politically, economically, and culturally impossible to do so. Protesters should accept this reality so both mainland China and Hong Kong can work toward building their combined future. Outlandish incidents like this one have no place in these efforts.