In my observation of life in general, most “officials” in a situation side with the bully. I’ve seen it over and over in multiple settings. If the victim fights back, they punish them. Unless, somehow, the victim manages to “beat” the bully. In today’s schools, no fist fight to settle it is allowed any more.
My son who was very, very small for his age got in trouble for retaliating against a much larger kid in middle school. However, both boys were called in and so were both sets of parents. The boys became very good friends after that. Like you said though, my little son was called in first.