and about "smearing" tom's name....that's what Janeway and tuvok wanted. Remember Tom was purposely acting like a jerk to make it believable that he was leaving. Neelix, like everyone else, believed it like they wanted
There's a huge moral difference between someone acting like a screw up and calling them a traitor. Mind you his "evidence" of that was -after- he broke into his quarters and used someone else's authorization to hack into Tom's computer.
Only after that did Janeway and Tuvok say they could use that to possibly flush out the killer. Mind you this was after they asked Neelix to step out of it. No... he was completely unselfish by putting his own headline ahead of the ship's security.