Read the whole page.

many states have "stop and identify" laws that explicitly require a person detained under the conditions of Terry to identify himself to police, and in some cases, provide additional information.

Do you have details we dont? This man could have said he was one person, the cop ran his name and the suspect didnt match the photo on file. We dont know.

the U.S. Supreme Court established that police may conduct a limited search for weapons (known as a "frisk") if they reasonably suspect that the person to be detained may be armed and dangerous.

We did not see the events leading up to this video. SO we have no idea what the man did or did not do beyond the fact that he was IN THE VIDEO resisting arrest.