Got a theory due to the fact of 2 reasons.
The first is that when Dallas played Carolina on Thanksgiving, the radio commentators were saying that when they were on the field, it looked like Carolina's colors were very bright on the field (due to the rush colors). As the game went along, they were saying that possibly their offense were doing well in the first half because it was easier for Newton to see clearly where the players were due to the darkness of the stadium and the bright jerseys. Also, they said that Carolina's running game was working well because it was easier for blockers to see white (sounded like an excuse but you never know)
The second is week 1 game last year with the sun being a factor in the 2nd half. With Dak passing, I wonder if sometimes the receivers couldn't see him throwing the ball as he was trying to get the ball out quickly. Yes, Romo played under the sun too, but Romo moved a lot, held on to the ball for long periods of time, and he threw the ball a lot further in the 2nd half when the sun became a factor.