I do understand that those whose family members DO actually die can be assumed liars, on the precedent of many going before. If this had ever happened to me, I would have brought in an obituary myself, to prove it, whether the prof had asked for it or not.

I do recall at least two professors mentioning this phenomenon, and this was back in the 80s. One said in particular "I don't want to have the blood of anyone's grandmother on my hands over my exam schedule..."