Why does the leader attack the owner?

It is normal for sheep to attack people.

The general recognition of people, because adults have not experienced it, they generally believe that sheep are not aggressive, so your experience is just a joke from the adult point of view, I understand your Mood: When we were children, we, brothers and sisters, heard the roar of tigers in the mountains, and the adults in the family didn’t believe it.

Maybe that sheep is protecting its child, and the distance you keep from the sheep makes it feel that its child is threatened, so it strikes preemptively.