By Pat Padua, Special To The Washington Post Would anyone who works for an online business really not have a Facebook account? The toxic relationship thriller “Unforgettable” hopes viewers won’t remember its pesky plot holes, but despite a mostly uninspired cast this predictable film eventually builds a campy momentum. We meet a scarred, shaken Julia (Rosario Dawson) in classic noir style as police interrogate her about a murder she claims she didn’t commit.