Gordon told Assignment X that he had originally written the character's death scene as part of the final episode, which aired on May 24.
"I... wrote that scene and in the end it felt too depressing," he explained. "I think it would have been a really depressing moment [and] I don't think it would have been surprising."
He added: "In a strange way, [Jack's death is] probably the ultimate tragedy and probably the most politically correct ending, but it wasn't something anybody wanted to commit to."
He also revealed that President Taylor (Cherry Jones) would have been implicated in Bauer's demise.
"She would try to save Jack and it would have have been too late," he said. "Like Romeo and Juliet, it would have been the function of the timing of it."
Gordon previously confirmed that a film adaptation of 24 is currently on hold.