Bringing in a Sub after free throws.

[Derrick]

During a summer league game. We had a discussion on when to bring a substitute in during free throws.
Situation: After the first of a two shot free throws there was no sub a the scores table. Then after the official bonce the ball to the free throw shooter a sub went to the table. One of the official during the game said that because the ball was in the hands of the free thrower that the sub could not enter the game. However, after a made free throw the ball become dead until in the hands of a team for a throw in. So, with that should the sub had enter the game?