Jane and RJ is just like Gibbs with Hernandez in NCIS.

Hernandez murdered Gibbs family so Gibbs killed him, Abbey and the rest of the team, including the director ! found out that he killed him and THEY WERE OK WITH IT AS THEY KNEW HERNANDEZ HAD MURDERED GIBBS WIFE AND DAUGHTER.

RJ didn't just cause a car crash that killed janes family he butchered an 8 year old girl and her mother.
Seriously what is Lisbons problem with jane killing the man who slaughtered his family ?