Ah yes, having watched the video - it was a case of riding dangerously.
From both the persued and pursuer unfortunately! It was apparent from the reflections on other vehicles that the pursuing officer wasn't using blue lights for the majority of this footage.
That could have:
given the biker the impression he had been joined by a fellow biker for an impromptu thrash
encouraged him to ride faster and more recklessly
endangered other road users - it certainly didn't warn them of the danger approaching
Seems like the juicy conviction was more important than public safety!