If you're a team with limited depth, injuries absolutely can and do derail seasons. Even great teams have a hard time winning if they have injuries at key positions. I'm not putting this game on injuries tho. Shaheed muffing a punt and Carr throwing a freak pick 6 hurt.
That said, the going for it on 4th when not necessary bugs me. Kick the FG and take the points. Both the last 2 games, those points off the board were the difference in the game.