Citation in examination In a course, the professor sets an open book exam with the restriction that students can use only class notes and textbook in any electronic device(mobile, laptop, etc). In short, no internet during exam. 

A student came across few previous year exams from another university which has exact same syllabus for the course. The student went through these exams(with solutions) one day before the exam and the student could remember most of it. It turned out that the exact same questions appeared in that student's exam next day. The student wrote down similar answers.

Now the professor accuses the student for academic dishonesty and says that the answers should have been cited in the exam.

Questions:


Should the answers be cited by the student in exam? With no internet access how would the student get the link of reference.
Should the questions be cited as well by the professor in the exam. Even these are taken from another university exams (word-by-word) ?
Does academic integrity apply to only students or can it apply to even professors? Can any action be taken on the professor if any student happens to have lots of evidence that not just exam questions but all of the coursework including slides of powerpoint are copied from another university coursework with no sign of citation?
If the case is fairly stated then the professor is not being reasonable. Students shouldn't have to cite what they study prior to the exam. In fact, in order to provide a proper citation the student might actually have to return to the site to get the proper citation, breaking the rule in order to uphold it - Catch 22. 

However, since "innocent until proven guilty" may not be the operative standard (sadly) it may be difficult for the student to make the case. But it is worth making and should be made forcefully. Appeal to higher authority if necessary. 

I will leave your last two questions unanswered as they are treated elsewhere on this site and don't really affect the outcome for the student, which I treat as paramount here.