The initial serve was an out and the server knew it. The opponent kept playing and the kid kept looking back to the camera wondering why the opponent hasn't stopped playing. So when the opponent returned the i think its called drop shot? don't quote me on that, he lost the point. Even then it's just a friendly game, not even a competition so you don't need someone to call out ins and outs. What i'm more confused about are these angry people calling the kid stupid in a match that has no referee.

I assume you're supposed to hit a serve onto the opposite half of the court from where it was served. I have no idea though and I don't care enough to Google it. All of the people explaining in the comments just keep saying "it was out" without explaining what that means.

@@DockClock-rp2ro u see those white lined boxes in front of the net (and behind the net from the kids perspective)? Inside that box means in, outside the box means out. If the first serve is outside of the box then it doesn't count and the receiver isn't supposed to hit it back. However if no call is made then the server should continue playing. I mean if you don't know you don't have to answer... especially if you didn't bother to google