I doubt he does his own grocery shopping, because he doesn't have to, and also because of the exact reason you posted.
Having said that, if he were in a grocery store and I saw him, I'd be right at your side to ensure that piece of shit knew what I thought of him.
Even when it is not deterministic at a single event, it is at a group of events. I know that sounds contradictory, and there is probably a better way to word that, but for example - if quantum randomness means that you cannot predict where a specific particle will go each time you measure it, you can predict the distribution curve of where the particle will be if you measure it some arbitrarily large number of times.