Frustration

When school started this year Brennan we assigned a safety post. In order to balance the responsibility, we assigned the duty of walking Ry home to Tobey. Tobey is always trying hard to be 'cool' like Brennan. Riley is always trying hard to annoy Tobey and Brennan. Every day when they walked past Bren's post, Ry tried his best to be a snot. A couple of times I walked up to school to view the mischief myself. One day Tobey and Ry came home crying, both of them. Ry had scratches and dirt on his face. What happened to you? I asked Ry.
"We got in a fight."
Tobey quickly interjected. "Chris was trying to beat up Riley and I had to defend him."
Chris is Brennan's friend, a 5th grader. He has a sister who is in 1st grade, and apparently Ry was picking on her when Chris interjected.
"So Chris hit you in the face?" I asked.
"No, Tobey did."
What? I couldn't figure out how Tobey could defend Ry by hitting him.
Here's what Tobey told me: He wants Chris to be his friend too, so he can be like Brennan. He saw Chris picking on Riley and defended Ry. Then as they were walking home, Ry was talking about what a jerk Chris is. Tobey listened to it as long as he could, but about half way home couldn't take it anymore. He wanted to be Chris's friend. Frustrated at Ry for being 'such a brat', he asked Ry to stop talking about it, and when he didn't, Tobey jumped on him and beat him up, throwing him to the ground and punching him in the face. Tobey said 'he just couldn't take it anymore'. He felt bad he had to hit him, but he had to make him stop.
So, I sat there trying to figure out how to come up with a consequence for either of them- Tobey for defending/beating Ry, or Ry for being annoying but getting beat twice. I'm not exactly sure where there was a lesson to be learned, but hopefully they learned something. Ry certainly wasn't going to stop bugging his brothers. Tobey wasn't going to stop being frustrated with Ry. I decided to let the whole thing go and head to my room to pray for serenity. I think "serenity now!" was the exact phrase I used...