Not only would he be guilty of assault, but also of sexual assault. The fact is, children have the exact same emotions that adults do in the same situations, the only difference being in how they may react to these feelings. In fact an adult may be more likely to suppress a healthy show of emotion, causing himself long term psychological damage. Our children deserve the same legal recourse from physical assault that we do. Spanking is a lazy parenting method.
Spankers typically put little thought into parenting, but mainly react.
The time and restraint that it takes to guide and teach a child effectively may not be the quick fix we are looking for, but there are no quick fixes. Spanking has its price in the long term.