It was flagrant to me. The ref appears to have talked to them early in the match at the center. When the kid got to his feet at the end he nails his opponent in the back of the head, and then continued to pound on him as they went out of bounds. He was slugging him or trying to at that point and had lost his composure. That all happened pretty fast right at the end. Match over isn't the wrong call. Hitting your opponent like that is by rule flagrant.
Could it be called unnecessary roughness or unsportsmanlike? Sure. That would have been the "safe" call to avoid being criticized for making a big call in a big match. The ref could have sent each wrestler to his coach, had a little visit with each, and restarted.
The kids leg was obviously messed up and he wasn't hardly able to hobble around on it. At one point it looks like it gives out and he's falls to the mat. Hope he heals up.
You already have admitted that you are a part of the pussification effort!

That was NOT flagrant. No way. A right cross and an upper cut would have been flagrant but not a little tough clubbing. Both kids were aggressive and we have ZERO idea what the official said when brought them to the center and talked.
The official to me did take control of the match. He stopped it early, took them both to the center of the mat and had some words with them. His body language indicated to me that he was trying to calm the situation down. He put his hands on their backs and spoke to both of them and looked at both of them while he was talking. Additionally, right after the following whistle, the first time they tied up was pretty soft.
That said, I'm with Rford for the most part. When the kid gets out at 2:06, he clubs the head which is good physical wrestling, but when they are going out of bounds he basically bitch slapped the kid 3 times, and missed on the 4th, and he was swinging too. Had it been a one/two combination, maybe he gets away with it, but to follow it up with a third and fourth................. I'm sorry, but I think the ref made a good call.