In the NYT article it sounds like he intentionally collapsed and then they took him to the hospital. From the above link it sounds like the police just took him to the hospital because they wanted to.

"I have been arrested 9 times. The proper procedure for police is to take the arrestee to a magistrate. This happened twice. On 7 occasions, I was taken to hospitals (3 times to NY Downtown Hospital, 3 times to Bellevue Medical Center, and once to Saint Vincent Catholic Hospital)."

I can't help but think of the recent case of the NYPD who was forcefully admitted to a psych ward because he was a whistleblower.