Edit: In the spirit of trying to actually add some worthwhile content in my comment: Harassment sucks, just like not knowing a core skill of one's job, sucks. But demanding perfection in either case is not a reasonable approach. When someone joins, and they don't meet expectations, you have to tell them they didn't meet expectations, show them the difference, let them know what the expectations are, tell or teach them what they need to know, and give them a chance to remedy it. You document this and all related conversations, in the presence of a third party if possible... usually and preferably an HR rep. If expectations are not met after this point, you are now fully able to eliminate the possibility something was inadvertent, accidental, or due to ignorance, and you have solid grounds for disciplinary action. Most times the employee will learn the lesson and it will never even reach this point.
When this woman requested a big deal not be made, she was talking about the type of panicky hyper-sensitivity on this comment thread. MY PRECIOUS GENITALS!!!!
Life is full of easy, simple snap-judgments when you haven't lived much of it yet.
Firing someone is costly, and in more than one way.
People can learn. Think of stuff you did ten years ago, that you cringe at now. You know better now. You learned.