Who throws the dice for you?

[Anomalocaris]

It's not a hand wave. Event is a menifestation of change over time. According to quantum mechanics, time, like matter, is not infinitely divisible. There are fundamental units of time, just as there are for charge, mass, space. There is no meaning to what happened before and what happened after within one Planck time, just as there is no meaning where exactly it is within one planck length. So there is no meaning to causality on the scale of planck time. So by this interpretation of quantum mechanics events happening on planck time scale is truly random (in a statistical sense), not menifestation of deeper mechanistic causality.