Their replacements - Lovett, Wallace, Jackson have played extremly well IMO there's not much of a let up there, but you do lose your leader and signal caller in Square which may have been a factor in a couple of big plays they allowed this week and last week.
But honestly, time and again I have seen it on other teams when a defense keeps stopping the opponent and giving the ball over to the offense and the offense continually pisses away the possessions, at some point their hearts just go out of it and I think that could have happened to our defense today.