I don't think its quite that easy. This case, is at its core, a case of copyright and intellectual property. Both the UK and US are signatories to the Berne Convention, as are 162 other countries. This isn't something that can be avoided by national boundaries. It comes down to whether you want this tried in the courts of the US or UK, or if you'd rather roll the dice and let the World Intellectual Property Organization take it to the International Court. The latter, I imagine, gets a great deal more expensive with a far less likely outcome for either party.