A lot of good things could have been done with this movie using essentially the same sets, plot devices and storyline. For example, why not plant a seed of Erica's capability before the murder of her lover? Why not develop Erica and the cop's relationship slowly and convincingly? Maybe contrast Eric's metamorphis by including some other post-event facet, relationship, etc., in her life that she now rejects? Why not have her injure an innocent bystander to underscore the wrongness in Erica's actions.
Instead TBO exploits the revenge fantasy to its maximum level, giving insincere lip service to the "don't do this at home" messages thrown in only to allow the film to qualify as legitimate.
I'm not a Jodie Foster fan. After displaying some range in films like SILENCE OF THE LAMBS, NELL and one where she plays the ordinary mother of a child prodigy, Foster has slipped into a succession of roles where she plays the same hard-bitten, badgered heroine single-handedly overcoming evil. Such is fine once or twice, but I'm getting too used to her "fight versus flight" close-up. TBO could have used a younger actress or one that more convincingly embraced being a woman in her forties (instead of 40-something Foster playing a younger woman).
TBO is a movie with substantial actors, financing and resources that manages to descend to junk.