Demetriou takes Ilias off against St George because he's having a shocker and, at that stage, the side has is down by almost 30 points in the first half. Demetriou realises the game is gone, and takes the opportunity of shocking the kid out of his comfort zone, and benches him for the rest of the game. The next week, he puts him straight back into the FG, and presumably, has a good long talk about what is required from him. He both teaches him a lesson and shows confidence in him. Ilias has played extremely well ever since.
Hook drops Sloan for a dropped ball against the titans, on a week end where all games were played in shocking conditions where even Tedesco made similar mistakes. He seems to have lost all confidence while playing reserves, and finally gets an opportunity about 10 weeks later with a spot on the bench. He's put on with 10 minutes to go when the game is gone. He gets on for 20 minutes the following week when the game is in the balance, but looks hesitant as if he's lost all confidence.
So you tell me which method teaches a young player a lesson while maintaining their development?