Gibbs never forgot that one moment of pure terror. He was getting a confession. It required some creative investigation techniques. It worked better with DiNozzo, but Gibbs could have pulled it off by himself. He brought Tony because he knew Tony really wanted to jump.
Tony was trying to arrest the marine when he fell. His mind wasn't on the jump. Gibbs would have strangled that marine if anything had happened to Tony. To say he was relieved when he saw Tony's chute unfurl would be an understatement. He smiled when he saw that white cloth billowing in the air. For Gibbs that was saying a lot.
He joked about Tony breaking his neck once they were back in the bullpen. Once they were safe and sound again. He laughed when Tony limped out because he could tell Tony was hamming it up. It was easy enough to laugh when Tony was down on the ground safe, but he had never been that scared about jumping, not even when he was jumping out of a plane himself.
He tried to rationalize it later by saying that it was because Tony didn't jump. He fell; he wasn't ready. He tried not to think about the last time he'd felt so scarred, when Kelly was being rushed to Bethesda in an ambulance coughing up blood.
Leroy Jethro Gibbs was a brave marine, and he would never admit to anyone how terrified he felt when his children's lives were in danger. But he would never forget that moment of pure terror.