The key numbers behind why we jumped 10 or 12 spots against DePaul (and they dropped similarly) are 39 and 22.
We allowed 39 points, a season-low for both us defensively and DePaul offensively. DePaul shot 22% on FGs. I haven't checked but I'm going to go with that likewise being a season low for us on defense and DePaul on offense.
Those numbers are far enough off the norm, they are going to cause larger than typical shifts in the Team Value Index on both sides -- and thus significantly affect each team's ranking.
Using the USC-Oregon State game as the example, the numbers on either side aren't outliers the way DePaul's were.