The first Irish pub in Hannover was run by Seamus and Geraldine MacGowan, both of whom were part of an Irish traditional band in the 70ies called "Oisín". While Shay rarely took a guitar in his hands after they came here, Geraldine kept on singing and releasing a couple of CDs. The guitar player on her latest CD, "Somewhere along the road", was a young guy named Shane
McGowan. That might be the one you mentioned.
Unfortunately it seems that her homepage geraldinemacgowan.com has vanished. At least google couldn´t find it ...
By the way, Shay once told me that he was second cousin to The Pogues` Shane MacGowan. But given that MacGowan might not be one of the rarest names, plus the Irish tend to spot a good story from a million miles away, I wouldn´t bet on it ...

"Just once I would like to see the coyote eat that feathered freak !" (Sledge Hammer)