So you're proposing that the physical punishment you inflicted on the boy fixed his "sociopathic" tendencies? And that telling the boy you witnessed his planning and intent will shame the boy into good behavior, rather than make him more sneaky about it next time? 

It wasn't good parenting or clear thinking that inspired your actions. It was your own shock, fear and negative feelings towards the boy that motivated you to hit him. I'm not saying you're a bad person. I'm saying your gut reaction was inappropriate, and may have had a negative influence rather than a corrective one. 

There is no act of a child that can't be addressed without resorting to physical punishment. We don't use physical punishment on adult murdering sociopaths. Nor should we inflict it on children.