Walking out of “Rogue One,” those not yet acquainted with Forest Whitaker’s guerrilla fighter may have been wondering what the deal was with Saw Gererra – or more importantly, why he seemed so important in the first place. After rescuing Jyn Erso as a child and promptly abandoning her when she was a teenager, Gerrera’s vicious tactics and terrorist-style methods of achieving victories against the Empire seem just a little off .