So, your argument that the defense was good was that they held the opponent to
less than their season average. Then you argue that the offense was also held below season average so the offense failed. Then you admit the opponents strategy was to burn up the clock. It seems to me, that if one team is trying to burn clock (instead of score) and the other teams defense has no answer for that, then the game will go by very fast and both teams will score less than their averages for the year.
Either way, it seems silly to hang your hat on a single game. It seems much more reasonable to look at someone's entire body of work to determine whether they are performing well. Statistical analysis is never very accurate when you rely on a single data point.