Basically, the French started making lots of noise in Paris, the German general in charge (I forget his name) decided that between the Resistance and advancing Allied armies he couldn't accomplish anything useful, so he basically pulled out (and violated his orders from Hitler to raze the city). As I recall, there was no real German presence for the 48-72 hours before the Free French 2nd Armored marched in. So yes, one could reasonably say that the Maquis liberated Paris.
As for Patton's role...the 2nd FF Armored and US 4th Infantry division were subordinate to Hodges' First Army, not Patton's Third. As far as I know, Patton was never intended or ordered to liberate Paris.