The young guard tries to holding his uncle at once when his uncle plans to punch the chief. He snorted at his futile attempt and hit him on the chin with his elbow. The young man that took a hit on his chin, lost his balance at once and falls on his butt. He then spat by his uncle, before the middle-aged guard shift back his gaze on the chief. All of this happens in a couple of seconds. I watched their drama as I keep silent, by the kingdom law, the chief was wrong to slap him first. Which make him legitimate to hit him back.