What's wrong here?

 A recent article about Eric Gales in Guitar Player magazine online included this snippet:

Like Jimi Hendrix, Jimmy Page and other blues-rock guitarists who were born with big hands, Gales makes great use of the technique of fretting the low E string with his thumb, which effectively frees his other fingers to embellish the chords he plays with added notes and “extensions.”

What's wrong here?

Eric Gales plays with the bass strings on the bottom! So if you think about it, that would be require a pretty unrealistic stretch for even the biggest of hands.

The author's right that Gales makes good use of his thumb, it's just that he does so to grab the high strings on the guitar. Unlike Hendrix, whose thumb was usually anchored as the root of a barre chord, Eric Gales uses his thumb to add funky extensions and alterations on top of his chords. 

Same but different. Quite a bit different.

That's part of what makes playing Upside interesting: even standard guitar shapes and techniques can evolve into whole different animals.