I've already said that in one of my comments. However, there is no video actually showing him using the pepper spray on the perp. If the Sergeant had used the spray, the perp would have had to be seen by medical staff. It's standard procedure. You can't get around that, and you don't want to get around it. You want to make sure that there is a record of the condition of the perp once he's received wherever he is being locked up. That way he can't come back and claim he was beaten by the cops who brought him in. And the officer using the spray would likely have to fill out a specific form if it was used. There's no info in the article on that either.
Anytime force had to be used on an inmate, or there was an assault on staff, or an inmate was stabbed, etc., it was called an Unusual Incident, and it had to be reported to Albany within an hour of its happening. In New York State Corrections, whenever an inmate was transferred into a new facility, he was made to strip, and pictures taken. The medical staff also had to see him. If he was involved in a fight, same procedure. If he was admitted to the special housing unit, a strip search was conducted by the SHU officers before he was placed in his cell. Then medical staff had to come to see him. They would make the inmate strip, and check his body all over, to make sure he didn't have any physical injuries on him.
Chemical agents were used rarely, but if they were required, there was a specially trained CERT team that did the extraction from the cell, and the inmate would have to be seen by medical staff immediately afterwards, to ensure that he had no adverse reactions to whatever chemical agent had been used.
You wrote “I see what could be something in the Sergeant’s right hand”
I simply provided a couple points from the aforementioned video, so that you would have more certainty.
Thanks for the details, re standard procedure of care.