Hoping this helps. When I was in high school I can think of one kid in particular that was very similar to the kid in the video. We will call him Harold for anonymity purpose. Harold was super loud, joyful, but definitely in his own world. From the outside teachers certainly thought people were being friendly to him, but it was exactly the opposite. He had exaggerated responses just like this and it made it "fun" to get that little rise out of him to ask silly little things.

To you it may seem like just fun banter. When you've witnessed this exact behavior I can promise you it's not. Its all about getting a laugh for these kids and they don't realize the long term damage it incurs. I will not judge you based on ignorance to the subject alone, but if you think this video is okay then I'd assume you are probably one of the kids who laughed at these interactions instead of telling people to just back off.