The definition of continents is not science. Purely from strict physical geography Europe is just extention of Asia or Eurasia. Where one ends and begins is open to debate. Israel is in Asia. Yet it is normalled given the privilage of being taken as European. For instance Israeli football play in UEFA. Israeli singers take part in Eurovision song contest. Cyprus is only 60 miles from Asiatic Syria or 40 miles from Asiatic Turkey but is always taken as Europe.
Thus if Cyprus can be taken as Europe when physically it is in Asiatic because of cultural, religious reasons [population is mostly Greek Christian with minority Turk] why can't Istanbul be called as "Asia"?