I can't imagine what kind of industry you work in that people would potentially do such a thing? And that whatever their allegations were, that the school would believe the nutjobs who call in?
I can, however, see potential problems with giving some employers too much advance notice that you are leaving. Again, depending on the industry, specific company, and its culture, maybe you would be treated poorly for the rest of your term there. Once you tell your boss you are leaving, he or she also could just say, "Ok, don't bother coming in anymore," and then you are out a paycheck until September. Those sorts of things would be my only concerns -- not fellow employee sabotage. But I've always worked in health care so maybe I have a more positive outlook on things...
PS The puppybowl is awesome.