So, I listened to what was happening between them and I have my conclusions.
I think the man has learning difficulties, maybe overmedicated, maybe substance, maybe he's himself. I think the mother is nervous because she doesn't know what his reaction is going to be with probably puts the officer ill at ease.
I think she tries to take control of someone she's dealt with before as she's arrested him at another point. I think this has made her overfamiliar hence her big bad police officer routine (it probably kowed him at their last encounter). At no point did she get onside with him to de-escalate this issue so tension raised all around.
And, yes, I agree with the other assessment of her not using the choices available to her.
I'm amazed that she didn't use the background knowledge of the arrestee as he's, clearly, been through some early years trauma before as he kept mentioning "sexual abuse" and didn't want to be touched (also an autistic trait in some).
What's odd is his lucid conversation about 'abuse of power', which threw me quite a bit, but then she lost her shit!
Not sure if the man would have lived if he were another colour, mind, but I found it quite interesting all the same.
The officer needs retraining big time!!