I appreciate you trying to find an excuse for Utah, but it's really not that complex. Right now Utah is not as good as the majority of the Pac12.
As far as the performance in the first 4 games following the BYU game and the last 4 games of the season, it's an interesting theory but the data suggests something else may be at play. Here are the winning percentages for the 4 teams Utah played immediately following the BYU game and the 4 teams Utah played at the end of the season.
First 4 Last 4
2011 0.513 0.340
2012 0.600 0.420
2013 0.722 0.596
I see a pattern.