This weekend I was a floor director for a 100+ scholastic/open event.
During the first round, two fifth graders were paired. White raised his hand, and I went over there. The boy said that Black was hitting the pieces with his pencil, and talking to his knight. I noticed that Black had some jerking motions as he sat. He did keep score, and there were no complaints about illegal moves.
I told Black that he should not hit or touch the pieces. I pulled White to the side and asked him to be patient with his opponent, who obviously has problems. I said, of course I would make normal rulings on touch move, but only warn him about distractions.
I talked to White’s father about the situation, who was understanding.
At the start of each round, I talked to this unfortunate boy’s opponent and parent/coach about the situation. There wasn’t another complaint about this child for the rest of the tournament.
In a similar situation I did the same and also assigned the player a board that was a small distance from the other boards (the adjacent boards also had disturbance issues with the player). Space considerations meant that it could only be one table from others, but that was enough.
It does bring into question what to do with players who have ADHD / other similar related disorders. (And potentially what duty a player may have to report conditions like that to the TD ahead of any potential problems.)
Although it isn’t directly related to your topic, the “worst” thing I’ve seen so far is a game observer who went into full seizure while observing a casual game. He hit his face on a table on his way down (which was why we called 911 right away.) There were other complications during his recovery phase which aren’t worth going into.
But it does pay to take First Aid and CPR classes, espeically for TDs. Must remember to get myself recertified at the next available opportunity.