A better example, though less likely, would be Texas A&M instead of Bama in the above example. A&M beats Clemson on the road and then has a late upset loss to ... Miss State or somebody and drops down and then barely edges UGA in a contested CG.
Clemson after the early A&M whomps everyone on their slate and rises to #4. A&M drops after a bad late loss.
Obviously, we're dealing with unlikely scenarios, so it's not going to happen in 20 years, probably.