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you should have emailed the prof. directly, not your entire class. doing it that way would avoid the whiff of impropriety
 
I hope you mean discussing an exam with a student who hadn't taken it yet. At all of the institutions I've attended students start discussing exams with each other about 20 seconds after they've finished taking the test. It is pretty unrealistic to expect students not to discuss exams they've already taken with each other.

Yes, I did in fact mean talking to a student who has NOT taken it yet
 
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