My problem with this is that the arrest was not really justified, at least by the evidence in this video.
Under New York law a citizen is not required to present any document of identification unless he is driving a motor vehicle during a traffic stop. He must only verbally identify himself. Even so, the officer had no right to retain the citizen's identification; he did so in order to keep the citizen there. Note that only after confiscation of the ID, during subsequent conversation, does the officer finally state that he trying to arrest the citizen.
Next, the arrest was for possession of a knife. In New York per Penal Law Section 265.01, it is a Class A misdemeanor punishable by up to one year in jail to knowingly possess a gravity knife. Per Penal Law Section 265.00 a gravity knife is “any knife which has a blade which is released from the handle or sheath thereof by the force of gravity or the application of centrifugal force which, when released, is locked into place by means of a button, spring, lever or other device.” The article about the video indicates the witness who filmed it says the citizen had an ordinary pocket knife.
But in New York City the majority of arrests for "gravity knives" have been for pocket knives (as exemplified by this video). Pocket knives contain blades which fold out of the handle like a Swiss Army knife. You can't just flip them open like a gravity knife, you have to pull them open. They are not against the law, but NYC has interpreted the law to include pocket knives.
HOWEVER, the act of resisting arrest was wrong.
The police officer's use of force is authorized under Penal Law Section 35.05 conduct which would otherwise constitute an offense is justifiable and not criminal when such conduct is performed by a public servant in the reasonable exercise of his official powers, duties or functions. The function, in this situation, was attempting to arrest the citizen.
What should have happened? The citizen should have kept his mouth shut except to identify himself and then ask if he was under arrest. If the answer was no, he should have asked if he was being detained. If the answer was yes, then he should have stayed silent except to repeat asking periodically if he was free to go. If the officer did a Terry frisk and found a pocket knife, no amount of talking would prevent the arrest in NYC, and keeping silent remains the best bet except to immediately ask for a lawyer.