coach. BYU's front 7 is inexperienced this year and they needed the secondary to be solid. Howell has not been able to give the secondary the time and attention it needs. Since the front 7 has not been able to rely on the secondary, they have been even less assignment sound than just their inexperience would warrant. When you cannot rely on your teammates, you try to do too much, you get out of position, and you make bad decisions. BYU needs to get a new secondary coach, or demote Howell and get a new DC.
On defense the inside LBs (2 on the field) have their own coach, the outside LBs (2 on the field) have their own coach, the D-linemen (3 on the field) have their own coach. The secondary (4 players on the field) has a coach that splits his time as DC. It's the biggest personnel group on the field for the defense and it is likely receiving the least amount of coaching and attention.