User blog comment:AYET/Additional stuffs about chapter 711/@comment-94.68.151.44-20130613154517/@comment-5962458-20130614155558

From the beginning the plan was to achive two goals: Destroy the factory and capture Ceasar.I believe Law wants the marines to be there because they will deffinately not let Ceasar be.He believes that whatever happens to him Ceasar will be arrested and he hopes that in the meantime Luffy will destroy the factory and then it's both goals achieved.His life may seem to be in danger but somehow he believes (and me too) that his sichibukai status can still protect him from being killed by Doflamingo in the presence of the marines.

I doubt that he was hoping to take DD head on all along.I also doubt that he knew about the Dwarves because he seemed surprised when he "saw" them catching the fish.