Perhaps apply a new style based onthe original but with the leaders turned off? That presumes the lines are in a different paragraph.
Otherwise, you might need to get fancy with nested styles and a character style that applies a custom underline to tabs instead of using leaders, but that will require a real pattern to which tabs get leaders and which don't.
A simple solution to this that I always use is to select the offending leader characters and apply a text color of "none". Voila--no visible leader.
No need to get involved in new paragraph styles, nested styles, character styles, etc.