Was it an upset? Sure. An anomaly? Almost every team has games by playing a good game and the opposition playing below there's. So if you want to say there are hundreds of anomalies each year, sure
We were a 31 point underdog to a top 5 team with a Heisman finalist at QB we've beaten once in the last 50 years and you still don't want to call it an anomaly? Hundreds of times per year? Closer to once in a hundred years.