There was a parallel story in Denmark where the Danish police prevented free Tibet demonstrators demonstrating during the visit of the Chinese president in 2012. It led to an official inquiry but the trail ended blind where the leading police officers giving orders to detain the demonstrators could not remember where their instructions came from and the electronic paper trail had been deleted.
To me the Danish story was less a story about Chinese influence and more about our democracy's separation of powers or lack thereof. How our most powerful politicians and their minions basically can have our police do anything even if it is obviously wrong.