Well they did go over that:
Lydian Dominant (1 2 3 #4 5 6 b7) or Lydian b7 is used mainly used with tritone substitution. It works because the #4 doesn't conflict with the 3rd of the dominant chord like the natural 4 does in Mixolydian.
BUT
The lecture they gave was quite a bit more complex. It started out with the seperation of altered extended chords and how to use the extensions to form diminished scales. Then it went on and I got even more