Is This Photo Illegal?

Yes, if it were taken in Hungary. Against the European Convention of Human Rights, Hungary passed a law that by next March 15 will require any photographer shooting in public space to obtain a signed “model release form”. This provision will be bashed by either the EU Court of Justice or the European Court of Human Rights (for the very same reasons I explained here), but it will take time and – first of all – a photographer that sacrifices himself on the altar of freedom.