I think the first mistake you made here was taking the test in the same room, "Chinese wall" or no. Not saying I'd have had the foresight not to do this but after reading this post it's something I'll avoid.
You could email the professor anonymously and tell him that you emailed the exam to the secretary right away upon finding the turn-in system down but you "overheard" or somehow otherwise discerned that someone used the technical failure to gain more time to work on the exam. Idk what he'd do with this information, maybe look at the "last modified" time on the word document or whatever format was used and penalize those who used more time.
I feel for your frustration and I think it was kind of shady of your friend to do that knowing she's giving herself an edge over friends and classmates. However, I also see her side. She's in a sort of prisoner's dilemma. She has an opportunity to keep working with no consequences, but so does everyone else in the class (besides you, at that point). There are four basic outcomes:
1. She takes the time and few others do, resulting in a great advantage to her
2. She takes the time and many others do, resulting in her leveling the playing field and not incurring any disadvantage
3. She does what you did, and if any others or lots of other end up using the extra time, get's mildly or very fucked.
4. She does what you did and so does everyone else, a completely honest class
"Studies" show that most people choose to look out for their self-interest in these situations and #2 is the most likely outcome. You were honest and you might end up getting a worse grade for it. That sucks really badly but I'd just be satisfied knowing that you did the right thing. Doing the right thing doesn't always have direct and immediate benefits. That's life.
TL;DR: Ratting out your friend directly is a bad call, you could send an email explaining the dilemma students were faced with and asking him if he's going to take any steps to insure that no one took advantage of the technical failure.
p.s. OP, you're not an asshole or a bad peron
Last edited by auntjulia
on Fri Dec 16, 2011 8:29 pm, edited 2 times in total.