He’s probably being taken out daily and the bodega happens to be near the point his bladder wants out. At that age aim is…not a thing.

Still, points are valid but OP coulda taken them aside privately, or raised it earlier (and probably would have found the caretaker would havd been amenable to cleaning up the mess themselves, you’d be shocked what you get used to in these situations). Instead they went straight to loud and public humiliation. That is what makes them the arsehole.