Critchlow- They still hadn't pulled his redshirt, so no he wasn't injured. He just wasn't high enough on the depth chart yet. They pulled his redshirt the following week v Boise after seeing that Detmer was not reliable.
"Beau Hoge started and was ripping you up until he got injured in the 2nd quarter" - You were up by 7. Yes you were winning but it was a close game and USU had the momentum at that point (we had just got a pick 6 off Hoge). Not saying the game would have gone the same but he wasn't "ripping us up."
"Koy Detmer (4th string walk on) came in and handed you the game because he didn't realize BYU guys weren't wearing white jerseys" - Yeah thats about right (except he was the 3rd stringer)
"Koy was so bad, they played the 4th quarter with a RB playing QB (Austin Kafentzis) AKA- 5th string" - He didn't attempt a pass and Detmer has in till the end of the game. Yes he played wildcat but that doesn't make him the 5th string QB.

Injuries are a part of the game. But the fact that the 3rd string QB wasn't ready, while knowing that he was second in line for that game is a problem for BYU. That shows issues with decision making and prep for the game. USU beat BYU back in 2014 with a back-up QB. In fact in 2014, USU had to play our 4th string Freshman QB for the second half of the season. He performed well. He was prepared.

In summary, the 2nd stringer that was playing well in a close game, got hurt and the 3rd stringer was not ready and USU (especially Jalen Davis) took advantage of that. That 3rd stringer got pushed farther down the depth chart due to his poor performance but he was 3rd stringer that day. The 4th and 5th stringers didn't touch the field that day.