As someone that's taken many people to the emergency rooms/doctors office while they were in custody, the picture is consistent with a restrained person sitting in a chair. Further, there would be no reason for her hands to be in that position unless in custody, and even going to a medical care provider, I've never heard of a police agency authorizing the cuffs to come off unless there was an emergency need. Unfortunately, one hit is simple battery or assault in most states, and is a misdemeanor charge. That looks like a repulsive act. Of course, without seeing the full video for context, we don't know for sure, but as he was fired I'd say it's consistent with him striking her.