Either C+ or B-.
My anger has subsided since the game, but I admit I was so pissed at the time of the Pats fumble I was quite pleased when he got laid out trying to tackle the guy that recovered it. Kind of a "serves you right" moment.
But I think the good news is he can overcome these gaffs by playing a little smarter. It's not like he's Assley Lelie who can't catch a 5 yard hitch without flopping on the ground. DT gets YAC, and that's gonna mean a few fumbles.