How is a song from C&V a potential b side to album done 9 years later?
It's a theory, but I'm convinced, that Green Day/Billie Joe wrote/recorded some songs - which are now on Uno, Dos and Tré - in 2002/2003, but it wasn't the right time to release them.
If you listen to "Supermarket" and "Private Hell" by Iggy Pop (feat. Green Day), you can hear the style Green Day may have had at that time (2003), "Private Hell" (correct me if I'm wrong) even sounds like a mix between The Network and Green Day. "Someone stole the master tapes" is, in my opinion, a simple lie.