There were and are other ways of dealing with events such as that described. Not everything needs the police or the courts to intervene.
The best approach might be for the father [sic] to approach the headmaster privately. If the father is not satisfied with the response, or if there are any further problems, the father would approach the chairman of the board of governors of the school, or the local equivalent, perhaps with a small group of other concerned fathers. If this fails to produce a satisfactory outcome, more official and public action would follow, possibly involving the police.
The aim is to protect the boy(s), the teachers and the school from harm rather than to “get” the headmaster and extract vengence. A caned boy whose parents make a fuss may get less support from classmates, teachers and future employers than is fair or just, especially in 1962.