The other guitarist was Nathan December, who was an old friend who used to manage Cole rehearsal studios in Los Angeles where my bands used to practice in the 90's. I remember watching a clip of R.E.M. and suddenly the camera pans past Nathan on stage with them. I hadn't spoken to him in years and called him, stunned, "How'd you get THAT gig? And where are my tickets?!" Really nice, talented guy - good singer/songwriter.
December! That was it. Great that you were able to reconnect with him like that, very cool story.