Yes, that is a very good point. The 'quantum leap' thing comes from the origin of quantum mechanics when things were not well understood and a struggle for understanding was going on and crude concepts were introduced. The more correct theory for atomic decays has been known to be quantum electrodynamics for a long time now. Since an atom is a thing that extends over some space the Feynman diagrams that contribute to it have multiple vertices and the whole thing clearly should be extended over space and time. It is nice to have experimental confirmation of this but it really is quite the opposite of unexpected.
