I agree that it's not Gord tapping his ring against the guitar neck. Now I am not a guitar player so I believe you players that it's not possible to do. But for the purposes of this discussion, the reason it's not possible is because I don't think Gord wears a ring on his left hand while playing. If you had seen him in concerts, even recently (before you-know-what), the obvious lack of wedding ring is blatant to those of us who look.
He once said that he's afraid it would catch on the frets. So if he feels that way about his wedding ring...I would guess that he would feel that way about any ring.
The caveat to this is that he did wear it during the taping of the Reno special out of respect to Elizabeth.