What's in a Pronunciation?

The father of my former co-worker Guy (who pronounces his name "Ghee") stopped in at the shop one day. He asked for "Guy," and when we asked about the pronunciation, his father laughed and said, "We named him Guy, not Ghee." Of course, my co-worker Guy is free to call himself by whatever name he chooses, but we're not talking about a name here, we're talking about a pronunciation. And as his parents are the ones who picked that name, they're the ones who make the call on pronunciation. In any case, it gave us one more thing to make fun of him for.