What's wrong with defining how children can be hit safely?
If it is true that a mild and occasional smack might not do much harm and may even be effective in stopping unwanted behaviour the short term, and that it is not in a child's best interests to have their parents marched off to court for minor slip-ups, why don't we just make it clear in law what sort of "smacking" is okay?
We don't do this for adults - why should we do it for children? It could be argued that children need greater protection than adults.
There are numerous problems with defining how children might be hit - how often, what with, by whom, how hard, what for, at what ages and so forth.
Chester Borrows' amendment to restrict the use of force to assaults that cause no more than "transitory and trifling" harm is fraught with problems - the primary one being that the term "transitory and trifling' is wide open to interpretation. Interpretation of the same term in Canada has led to the acquittal of parents who have been very heavy handed - for example administering slaps across the face.
It is necessary to ensure that parents are not prosecuted for minor infringements but such assurances should be placed in mechanisms outside the law.
It is unacceptable in the 21st century, with all we know about positive parenting, family violence and children's rights, that a new piece of legislation is being suggested that actually excuses physical discipline in any circumstances.