The guy was Damien's friend, maybe even his tour manager or something. But he definitely wasn't a fan, he was travelling with Damien and hanging around with Damien and Joel all the time
Joel was there, but not playing. He's on vacation, just following Damien on tour...
Anyway, the song wasn't What If I'm Wrong, it was a never heard before song for sure, something saying "what have you done to her smile / what have you done to her face / what have you done to her soul"... it sounded slightly political at some points but I could be wrong, I can't remember the rest of the lyrics right now... but I have a feeling Marti might remember more.
Something funny... during the aftershow, someone mentioned eskimofriends, and Damien said "eskimofriends... isn't it Emmett?" and someone (maybe Sharmin?) said yes and so he said something like "I love Emmett!"