Is it a sin to write a verse or hadith incorrectly, and does this imply it's permissible to cheat on an Islamiat exam?

I have seen other questions regarding cheating in exams but my question is only about exam/test of Islamic studies or Islamiat. Some people say that you can cheat in Islamiat exam/test because it will be a sin to write a verse or hadith in wrong words or in wrong order of words by mistake. Please clear my confusion that if it is allowed or simply I should not write it if I don't know it in exact words?