You've made this comment in two separate threads, and since I didn't remember it, I went back and looked.
Fancher had two incompletions on their last drive. One was their final play when he was pressured, scrambling, and basically tossed it anywhere he could as he was being tackled. The only other incompletion was nothing like you described: a receiver wasn't "wide open," wasn't 20 yards down field, wasn't directly in front of him, and definitely would not have been the game winner even if it had been completed. As the commentators said, it looked like Fancher thought the receiver was going to sit his route down. Regardless, this couldn't have been the incompletion you were talking about, as none of it matched with what you said. On his final drive, on a 4th-and-8, he threw a beautiful ball for over a tightly covered receiver for a 20+ yard completion in the middle of the field.
Here is the full game replay. You can skip ahead to the end of the game and watch FAU's final drive. What incompletion were you talking about?
Game replay:
https://www.foxsports.com/replay/fmc-wtxd8e1ewb2b968t
Play-by-play script:
https://www.espn.com/college-football/playbyplay/_/gameId/401628453
If you're talking about the second-to-last drive, then you've neglected to do a few things;
1) You didn't mention how the receiver was basically tackled, and then after the collision with the defender, the receiver didn't get back on track. He, for whatever reason, bent his route. Fancher's ball was thrown exactly where it should have been - up the field which was open. He would have no way of knowing the receiver was going to change his route after the collision.
2) You didn't mention that two plays before, Fancher threw a seed in very tight coverage. As the commentator said, it was such a good throw, that just a split second later would have been an INT.
3) Two plays after your referenced play, Fancher (list most of the game) was hit 1.5 seconds after the snap. Literally, he had a defender touching him 1.5 seconds after the snap. But instead of being sacked like most QBs would have been, he used his legs to get out of it, scrambled, and threw another seed while on the run for 10 yards.