harmonics?

I have been fooling about with the song ' Tequila' , the version covered by Arlen Roth and Danny Gatton on Arlens album ' Toolin' Around'.
The problem i am having is getting the swept harmonics effect ?.
The studio session is on You Tube . The effect is done by Arlen half way through and by Danny at the very end. Can anybody tell me how this is done as it has lost me complety.

Not sure if I understand what your talking about, But I the only harmonic I saw was a normal harmonic played, then while it's ringing, he used the whammy bar.

Only harmonics I saw/heard was early in the tune an artificial harmonic, and around 2:14 you see Arlen simply touching the fretted note 12 frets above for the harmonic. As to the end, Danny is using his pinky on the volume knob to make the sound swell, a trick a lot of Telly players use. Best I can tell after one look. Maybe cuz they're using Tellys using the bridge p/ups it only sounds like harmonics? I'm no sweeper, but I figure the only way you can sweep harmonics is if you had your guitar tuned differently; I'm reasonably sure they were in standard tuning.