Not too hot on theory myself but Satch doesnt seem to use any one particular scale. One thing that I know he does do is shift in and out of modes and drops in a lot of chromatics/accidentals when he is doing pentatonic runs. Basically, try playing a lick in a pentatonic scale anywhere on the fretboard over a backing track. Then play the same progression up a note, then up 2 notes etc - that's the basic concept of modes. You get totally different flavours for the same grouping of tones/semi-tones. Experiment with this and you will see a lot of where Satch gets his sounds from.