Does it matter? It was a long time ago. No bones were broken; no blood (so far as I know) was drawn. Eight boys had their bottoms tanned for offenses they had not committed. So what? So wicked dolts like that headmaster who cannot trouble themselves to discover the truth should not be allowed to administer canings. That is all. It should not be allowed.
Whatever benefits of moral correction are supposed to flow from corporal punishment justly administered to the guilty (I do not believe there are any), none result from being punished for something you have not done. A child may learn, from such unearned punishment, that the world is harsh and unfair but that lesson can be learned through study and teaching.