This is another story spawned by Last Man Standing. At the time of watching LMS, I couldn't believe that Gibbs swallowed so easily that Langer was the bad guy. He knew him; he'd worked with; he recommended him to NCIS. And whilst Langer had maybe not been what Gibbs had expected/remembered, I still don't believe he believed in his guilt. Then I was re-watching Tribes and saw their interaction there - Langer even went to Gibbs's house. So I'm even more certain that Gibbs has not accepted that Langer was the guilty one; that just wouldn't be Gibbs - hence this story was spawned