Perhaps the police officer thought that the boy was a Palestinian, in which case the policeman's behavior was, of course, justifiable. On the other hand, the Jewish boy now has some idea of how Palestinian children are sometimes treated by Israeli police. Anyway you look at it, it's a learning situation.
Justice Ministry: Information examined by AG about Gal Hirsch didn't come from police (Haaretz)
from the article: Israel Border Police beat, detain 9-year-old Jewish boy in Hebron