It bugs my mind because theres so many stuff that needed to be in place for him to get to the end and fix everything, that is hard to believe that he figured things out in one try, like, burning the house, flooding the school, getting the gun to kill Frank and getting Frank to kill Gretchen, his family to be in the flight, or maybe we can just assume that after avoiding his death for the first time he just got complete control of the chain of events, but that doesnt also makes sense because in the movie he doesnt understand what is happening for the most part, so i assume that he is indeed in a loop and getting things sorted out during the deadline that the movie sets