Thanks for posting this, I hadn’t seen this before.
I was a big fan of Guthrie’s lessons on Lick Library and his columns/transcriptions in Guitar Techniques magazine back then. I remember the clips of the Tone Merchants clinics (where he was a rep for Cornford amps) started appearing online in about 2004. It’s hard to believe that was all 20 years ago.
I haven’t watched it all yet, but so far the advice is similar to what he said in other lesson videos at the time, and in his Creative Guitar books.
EDIT: Interesting section at about 32:28 where Guthrie is discussing tapping with multiple fingers. Guthrie mentions that the finger combinations (2 3) and (2 4) work well together for him, but that (3 4) is problematic. He mentions that he’d happily believe what he has read in a piano book about (3 4) being weak for everybody for everybody, except that almost everything Paul Gilbert does is based on (1 3 4).
Guthrie’s conclusion is that you can probably train your hands to do anything, but Paul clearly demonstrates interdependence between his second and third fingers, and distaste for (2 3) combinations.
The truth is, there is progressive variation in the anatomy of the hand among the population, we don’t all share the same underlying anatomy. In particular, there is variation in the anatomy of extensor digiti minimi (EDM), which extends the pinky. For some people, EDM pulls on the ring finger, and so (3 4) combinations are likely to be problematic. For others, EDM is more free of the ring finger, but the ring finger now cannot be extended separately from the middle finger, so (2 3) would suffer as a result.