Zone, and 3. Playing an experienced mobile qb that was throwing darts on third down to receivers who made play after play 

The biggest mistakes were the pick in the endzone and the pooch punt. That is where the game was lost.

On the pick, I thought the ball had been tipped because Retzlaff had to throw over a jumping defensive lineman trying to tip the ball, but what I think happened was Retzlaff tried to lob it over him and ended up underthrowing the pass. He should have pulled the ball down  or thrown it away despite whatever play call coulda, shoulda, would of been made instead. 

That pooch punt just fooled BYU big time. It was perfectly executed and looked like a pass.

Then you have a 4th and 6 that turns to 4th and 11 because of a mental error to make the comeback even more difficult. 

2. Red zone stalling- Have to score TDs and nobody stepped up to make a play. You can blame play calling all you want, but the real issue is execution. 

3. Daniels made very few mistakes and put the ball right where it needed to be where his receivers could make a play. And they did even with good coverage (later in the game). Earlier in the game there were several blown coverages they took advantage of. Daniels is mobile enough to throw under pressure.  I am most bugged by the blown coverages and the push off that led to their first 3rd and long conversion that ultimately was a td drive. 

Officials seemed bent on making sure they didn't bail BYU out for nothing.

BYU got outplayed and definitely got out coached on that pooch punt.