The sack Pikula missed on Nevada first possession of second half. It was the 3rd and about 20 play. He just lunged into the QB with his shoulder. QB bounced off and ran for about 15 to set up 4th and short. Nevada converted and scored a TD.
Force the punt and Nevada doesn't have confidence on offense to take the 14 point lead.
On a larger scale, tackling with just the shoulder needs to be addressed. Bronson missed making a play vs UCF for the same reason, and Craig Bills probably wouldn't have concussion problems if he cared more about making a good technique tackle instead of delivering the biggest possible hit.