[Shades of Gray]

I have twice seen Ts revoked, once in a men's rec league game and once in a boys varsity game. The rec league T came after the ref made a call and turned to report it. At that point a spectator threw the ball back to the ref, hitting him in the back of the head. When the ref wheeled around and saw a player laughing, he immediately signaled a T and ejected the player from the game thinking that the player had thrown the ball at him. Fortunately, his partner had witnessed the indicident and after a conference with both coaches, both the T and the ejection were revoked.

Second time was an administrative T for having the wrong number in the scorebook. After the T was called the Visitor's coach showed the book that they had submitted to the official scorekeeper, who had copied down a number wrong. After this was shown and the official scorekeeper agreed the error was his, this T was also revoked and play continued.

Not sure if either of these are allowed by rule, but the outcome seems equitable in both cases.