Here is the video [1] with complete context. Unfortunately I've yet to find a complete translated transcript. But from what I've read (from potentially unreliable sources) the casters said 'Go ahead and say those 8 words and we'll wrap up here. There's nothing else to talk about. Let's lower our heads.' He then said 'Liberate Hong Kong, revolution of our time' while wearing a gas mask. Guessing that's 8 words in Mandarin. They then laugh and clap.
This is actually the thing that most frustrates me about these protests and issue in general. Finding complete, in context, recordings of the critical events is so incredibly difficult. This makes no sense since we are now in an era where everything is on camera from 500 different angles. But it is what it is. And of course providing in context video gets downvoted, because it makes the issues look less black and white. But that to me is the clearest example of idiocracy. We should not seek to create Hollywood villains and heroes in how things are presented. People should make judgments based on reality which, almost invariably, is more of a million shades of gray rather than good vs evil, right vs wrong.