Chez Chesler

Please see BostonHerald.com, June 8, 2004, "Cape pol arraigned in domestic assault":

A Cape Cod politician running for state representative from Sandwich was arraigned yesterday on charges of assaulting his girlfriend, authorities said. ... "She said he grabbed her by the arm, she had a visible red mark on her right wrist," [Sandwich police Sgt. Michael] Nurse said. Blank told police, who responded to a 911 call from the home, that his girlfriend hit him first, but authorities could find no injuries on him, Nurse said. The mark was apparently made by a bracelet worn by the woman...

I understood that one is permitted to use force in self defense, proportionally against force or threat of force. Is there a different standard in Sandwich that one may use force in self defense only after the aggressor has left you with a visible injury?