Capablanca described what he considered "the main rules of chess"
"1. Any piece that is touched must be moved....
2.Moves must not be taken back. If a gross mistake is made and the game is lost thereby, there is only one thing to do--resign gracefully and begin a new game.
3. Do not hover over the pieces too much. It is unethical and leads to errors. ... It is not bad to move quickly, but it is bad to move hastily."
This was in his book devoted to beginners of the game, A Primer of Chess.
Some people don't like the use of words such as "ethics" when applied to chess. But these are precisely the words used by Capablanca and other greats of the game.
(I was really impressed by the comments on this game!)
A terrible ruling. Even if the player knocked over his own King by accident, there is no requirement to say "j'adoube" at all. The rule on "touch move" is if you touch a piece with the intent to move it, you must move that piece. Accidental touches do not invoke the rule.
And in the case of a spectator knocking over a piece, this is ridiculous. The arbiter was an idiot, and I would happily have told him so to his face.
In fact, the "intent" clause has been removed from the rules, since it is nearly impossible to prove intent.
However... the newer version of the rules specifically refers to "touching a piece on the chess-board".
From FIDE's own web-site:
Article 4: The act of moving the pieces
4.1
Each move must be made with one hand only.
4.2
Provided that he first expresses his intention (for example by saying „j’adoube“ or “I adjust”), the player having the move may adjust one or more pieces on their squares.
4.3
Except as providedin Article 4.2, if the player having the move deliberately touches on the chessboard:
a.
one or more of his own pieces, he must move the first piece touched which can be moved
b.
one or more of his opponent’s pieces, he must capture the first piece touched which can be captured
c.
one piece of each colour, he must capture the opponent’s piece with his piece or, if this is illegal, move or capture the first piece touched which can be moved or captured. If it is unclear, whether the player’s own piece or his opponent’s was touched first, the player’s own piece shall be considered to have been touched before his opponent’s.