If the above situation happened as the client claims, then the artist is in the wrong. He asked, she said no, he went against her wishes. But! This brings up an interesting point. Does a tattoo artist have the right to sign his name to his artwork? Should he even have to ask permission, and does the client have the right to refuse?
Any other form of art is expected to be accompanied by a signature of the artist - a sketch, a sculpture, a painting, whatever. But most tattoos are not. But why not? Doesn't the tattoo artist deserve the same kind of credit and have the same right to sign his work as any other kind of artist? Or do the rules change since the "canvas" has a mind and rights of its own?
Personally, I'm not sure if I'd want signatures under all of my tattoos. But at the same time, I think an artist that works hard to create a beautiful picture should have the right to sign it. What do you think?