You're right, of course (i.e. they DID block better). But the thing about it is, I wonder if the OL pass blocked that much better, or if the Cowboys' defense shat their pants when Martz figured out how to beat that "send the house" defensive blitzing strategy. Previously, that was something Bears' OC's couldn't figure out. Now, however, that's not so.
I don't even know who their DC is, but as we have painfully learned, not all Coordinators in the NFL can make game time adjustments.