Watched the replay, was maxcontacts indeed. It's not about the amount of bodyparts touching the ground, it's about the amount of bodyparts touching anything, including your opponents body and the ground. In this replay both your toris were so close to each other that the amount of places where you 2 had contact exceeded the maxcontacts, thus preventing the dq. As mrmiyagi said, best you can do is ungrab and try to push yourself a bit away to remove some contacts and hope he dqs.