I remember similar scenes during my school years in Korea. By God's grace, I was never hit by my teachers like that. But the teachers used to hit their students like that accusing them of lacking absolute attitude. They also said that they hit them because they loved them. The teachers called the stick 'love stick' that they used to hit the students.
I feel very sorry that such a thing is still happening in Korea. The UBF system of training and discipling is very much similar to Korean education system and its ideals.