as gabester has noted, sometimes the sorted results of Spotlight are just wrong.

This has been a "feature" of Spotlight for several iterations of the OS.
I can recall a number of times when I would search for an item, see the list out of proper sequence, and then moments later, when I checked back to that list, the sequence was different, and still not in correct order. As if it thought the size of items was changing moment by moment.
(in these cases, I was searching for fixed size items, not cache files)

One of the many reasons why Spotlight has never been my favorite.

(It is sad... they took a good Find procedure that worked in Panther, added some good idea extras, implemented them in a mixed bag fashion, and then really messed up the user interface and basic Find functionality in Tiger, etc. It has never recovered.)