Well, he can tell his employees beforehand to only accept such order if he is in the US. Otherwise the documents should not leave the country. Then he would hav

Well, he can tell his employees beforehand to only accept such order if he is in the US. Otherwise the documents should not leave the country. Then he would have to reply that he is unable to provide access to the documents. Another reply suggested that he should have contacted the US embassy and ask that he is forced to commit a crime in the US by UK. This would have lifted it to a diplomatic level. From the circumstances it sounds possible that he wanted the documents published and was happy to be forced.