"Binding", in that the parties had signed the convention and agreed to "uphold" such rulings. They instead claimed that "Assange was free to leave at any time", i.e. that they were "upholding" the ruling. At the very least, Assange would be entitled to compensation as a means of enforcing the ruling, should the states refuse to comply. Which court would rule about such compensation is not clear to me. Perhaps the European court of Human Rights, but that is speculation on my part.