The momentum created from a game that happened 4 seasons prior to the 84 season?
That game was in 1980. The 3 seasons prior to that season, the total record was 29-7. The 3 seasons after that season, the record was 30-7. So, the momentum you claim carried them to the championship resulted in a cumulative record 1/2 game better over 3 seasons compared to the previous 3 seasons?
If you want to claim a play gave them momentum for the national championship season, then a better candidate would be Steve Young’s back-of-the-ball catch to beat Missouri in the 1983 holiday bowl that immediately preceded the 1984 season.