The more important point of McDonald is that Heller is incorporated (ie, binding on the states). The government argued that it was only binding on non-state enclaves (ie, Washington DC).
Justice Sontamayer's decision showed a total disregard for stare decisis, when she said "she could find nothing in the constitution guaranteeing the right to own a handgun". If she respected the court's decision in Heller, she would have treated that issue as settled law rather than use McDonald as an opportunity to undermine a concept already accepted by the court.
Do you have a link for that quote? Thanks