Just curious as to why you think it should have been a 21 to 28 pt difference? This Sooner team is untested, unproven and pre-season ranked on nothing but speculation based on returning players for multiple Div 1 teams and their schedules.
In the 3rd week of Dec, this game will be considered a W and nothing more.
Oklahoma is returning about 75% of their starters of a 9 win COVID shortened season including many key players. They had a full off season to work together against an unranked opponent who was displaced due to a natural disaster. Also, considering the slow start last year I would guess the team and coaches put extra emphasis on starting fast.
Pre season polls do not mean anything, except for the top 10. Without researching my guess is the last several championships teams were highly rated; i.e. what OU did in 2000 doesn't happen anymore. If your team is not ranked high in the pre season then likely they are not being talked about at the end of the season for the playoff births.
This win will be considered more than just a win IMO at the end of the year regardless of OU's: if OU is undefeated at the end of the year many will look at how close a perfect season was lost in the first game of the year to an unranked opponent - or - of OU falters anyone can point to the first game of the year as a predictor.
For these reasons and probably more I think OU should have beaten Tulane by 3 - 4 touchdowns. I also take issue with LR's initial response of saying he would never apologize for a win. No one asked him to but he can apologize for not having his team ready (again) and letting what should have been a blowout become a last possession game.