[homonculus]

"He mentioned being able to supply the dean with a list of people with 95% confidence that everyone who cheated was on the list, with no apparent concern for any false positives."

Right after that, he said that he couldn't be sure everyone on the list had cheated. He is saying that he thinks every cheater is on the list, but not everyone on the list is a cheater.

[paulgb]

Right, that's not too impressive though, the class register would have everyone who cheated on it with 100% confidence.