Having looked at the film, and heard the subsequent dialogue, my impressions are these -
Mr Lollie should have given his details to the female officer when asked, which he is required to do legally despite his protestations to the contrary.
The issue appears to escalate when the second officer appears and is instantly aggressive, provoking more protest from Mr Lollie, whoi already feels he is being unfairly treated.
Given that a third officer appears, and there is no obvious sign of any potential violence, it appears that tasering Mr Lollie is a ridiculous overeaction. As I understand it, tasers are only deployed by officers in fear of their own safety, or that of members of the public, which is clearly not the situation here.
The situation could have been handled far better by the femaile officer who was walking Mr Lollie out of the building - which would appear to be a desireable outcome to the incident.
The serious problems started when the second officer appeared and was immediately confrontational, overstepping his colleague's handling of the issue, which was at the discussion stage, until the second officer turned into a violent scuffle.
I do not believe Mt Lollie was necessarily singled out on the basis of his ethnicity, but he may have created an issue in the moments preceeding the arrival of the police.
It was extremely bad PR for the police, who spend a lot of time trying to advise the community at large that they are not heavy-handed and needlessly pgysical with ethnic minorities without provocation - and then proceed to be exactly that!
I am sure this man was released without charge - given that he was not formally arrested, Miranda-ised or advised of his rights before he was tastered, handcuffed and marched off to the police station.