She did apparently enjoy spending her free time rewriting a holodeck program to torture Tuvok just because he potrayed her in a less than flattering(yet very accurate) light.
She even worked in some C/S into it fanfic style! Not sure how she ever would've expected to get away with that if Tuvok had accessed that program while she was still on board, but long term strategy doesn't appear to be her strong suit.
Simple... The program was redesigned as a no-win scenario to kill Tuvok, and he was keeping the entire thing a secret back when it was a training program, so there wouldn't have been anyone to know he was in trouble and rescue him by re-writing the program from outside. Afterwards, it just self-deletes or blows-out the holodeck computer or whatever, and the crew is forced to simply assume it was yet another malfunction of the well-loved but suspiciously deadly sexatorium.