There can be a very fine line between humor and bad taste, especially when the joking is directed at a person.
One reason why I find the old line "Aside from that, Mrs. Lincoln, how was the play?" to be acceptable is I suspect that Abe Lincoln would have laughed at it. But the joke would have sparked a very different reaction in 1865 and I still have an odd feeling whenever I hear it. There would certainly be no humor in a joke about JFK's assassination.
That said, these Jimmy Hoffa cupcakes make me uneasy.
Is it the hand or the timing?