substitution question

exam question: A player who has been withdrawn may not re-enter before the next, opportunity to substitute after the ball becomes live following his/her replacement.

the correct answer ( per the exam) was false. rule 3-3-4 states "a player who has been replaced, or directed to leave the game shall not re-enter before the next opportunity to substitute after the clock has been started properly following his/her replacement."

I remembered that once a player was replaced he couldn't come back in until after the clock started, but the question talks about the ball becoming live. If the correct answer is false, I assume the distinction is between the clock running vs becoming live.

Another one that confused me was the following: A substitute who legally enters the game during a dead-ball period may not be withdrawn during that same dead-ball period. The correct answer was false. Following the logic of 3-3-3 and 4, a player is legal once he enters the court, and the player leaving becomes bench personnel. Is he not the "replaced" player and subject to the restrictions in 3-3-4?