And again this should surprise no one. One of the criticisms of Nolan and his defense was his complex system and constant reads would lead to confusion, overreading of plays, more reactive play, etc.
Moose made the comment during the game a couple of times, that at times the defense looked confused and not sure what they were supposed to do. We saw it in the Seahawks game where Aikman pointed out how it seemed like half the defense was doing one thing and the other something else, crystalized by the one TD to Lockett where Aikman pointed out it looked like half the secondary thought they were playing zone and the other half were playing man.
I'd be more willing to write this off as growing pains under a new DC, but the reputation of Nolan makes this seem like this is a feature of his defense, not a bug caused by no practice time.