IF Tennessee wins out, and Georgia beats Florida, and all three teams end up with one SEC loss, or Tennesse beats Georgia and Georgia beats Florida, and all three teams end up with the same number of losses, as well as division losses, then the tiebreaker is rank in the BCS.
Georgia would have a medium game with Georgia Tech, Florida would have a tough late game with FSU, and the Vols would have the end of season Vandy and UK. If some how the Gators lost to FSU, Tennessee would be higher than the Gators in the BCS, maybe even if the Gators struggled since the Gator loss to UGA would be late in the year.
It's a stretch I know, but it's a possibility.