That's a stretch, especially since it didn't happen in some isolated corner. They beat him up in front of a mass group of legitimate protesters who did not stop them. Even if the provocateurs are the ones who initiated the "legitimate" protesters are complicit too and probably joined in. I was in full support of the HK protesters, but not I'm worried they are turning into a dangerous mob.

I mean, what do you expect after 2 months of peaceful protests and no indication of any shift in policy?

I’m just quoting here, but this has seemed incredibly appropriate to these protests:

Those who make peaceful revolution impossible will make violent revolution inevitable.

When some of those protesters broke into the legislative council of HK, threw China' flags into the ocean, swung US/UK flags, beat up random drivers on the street.

They don't need the CCP to make them look bad.

How do these actions look bad to you, apart from "beat up random drivers"? And where you see the news of beating up random driver?

Does this action look bad to you? https://www.youtube.com/watch?v=YdxXCTpHARQ&list=LLFo7VgFlg9...

It does. That's why a lot of Hong Kongers stopped him to do so.