The way you describe boys reacting to the cane is far more drastic than the way boys have normally reacted to it in my experience. This could reflect the cane having been used far more severely in the cases you describe, it could reflect the pupils concerned having a lower than normal pain tolerance, it could reflect them acting up to expectations – if children expect a caning to be an absolutely frightful experience, perhaps they are more likely to react to it in that way, it could reflect a lot of things. But whatever caused it, it doesn’t match my experience.