The routes on this play aren't as interesting as the personnel and alignment. Texas comes out in 11 personnel and Bama matches with nickel (I think. I can't tell who the boundary underneath defender is). Texas aligns with Sanders wide left, Baxter wide right with Worthy near him, and Mitchell and Whittington in the left and right slots respectively. I'm not 100% sure what Bama's coverage is, but it's some form of 3 deep pattern match. It's not pure man because the only two corners align over Sanders and Baxter. The mike spies Ewers, while the will and sam reroute (not jam) deep routes before passing them off to the secondary and covering underneath. Because Mitchell doesn't go deep, the will covers underneath Sanders, and the boundary safety #6 looks for a potential deep crosser from the field. The star is manned on Worthy, and the corners and FS have deep thirds. Because of this, there's a soft spot between the sam and FS that Whittington settles in.
Why did this play work? Because we were in 11 personnel and it was still 2nd down, Bama didn't want to get out of nickel, and because of the respect they had for Worthy and Mitchell, they played safeties over the top of them. Could they have just played cover 1 with the star on Whittington? I suppose, but then all four receiving threats (Baxter wasn't really a threat) would have single coverage (the same would be true if they played quarters with the FS manning Whittington deep), and Sanders would be covered by a safety. By going with this coverage, they gained some form of double coverage on three of the threats, but the cost was a huge soft spot in the zone for Whittington. Also aligning in man would pull a linebacker out to Baxter, lightening the box and making a motion/jet sweep tough to defend.