I agree to some point - it would be best if it were possible to somehow comment on questions you gave the wrong answer to, why you chose that answer, but it would be difficult to organize that in a manner that doesn't allow you to pass that information on. Unfortunatly, cheating with exams happens a lot around the world, which is the reason for proctor services and all the measures taken (no phone in sight, special browser for taking the test, and so on).