I've gotten a lot of "well don't forget undebug all"-comments. A couple of clarifications here:
1) The lab is very stressful. It's easy to not think straight when you're running out of time. For every device that I forgot to disable debug on there are 10 that I did NOT forget to disable debug on.
2) I'm not even sure if debug was the issue. It could have been anything.
I could have gotten new questions that they hadn't had the chance to perfect the grading scripts for yet. I can think of several technology specific issues that I will not say out loud due to NDA. I said "do not fear the reread" and what I meant was; When in doubt; ask for a reread. Do not fear the statistics that more or less tell you to fsck off.
JUST DO IT.