Disagreeing Appropriately

I have another question for you. Sometimes when one of the children hurt another child and the hurt child comes to me and tells me they have been hurt, I ask them if they have disagreed appropriately with their sibling before they came to me. They reply, "how could I disagree appropriately, they were really hurting me." So, what to do in these sort of circumstances when they just need to get away quickly. I normally still do the correction with the child that did the hurting on accepting no answers, and also do one with the other on disagreeing appropriately. What are your thoughts? Thank you.