I don’t typically record things, but I could see the value in doing so if your kid denies having acted in a certain way, so you can show them they did. If they deny certain actions, it’s harder to show them that the consequences of those actions are related to the choices they made.
Of course, I’m not advocating sharing these videos with everyone, though. Maybe a counselor if necessary.
Showing someone what they did is not manipulation.
Calling it a manipulation tactic is, though, so you’ve just outed yourself as a narcissist. That’s a block.