BS”D
That is why you pay extra for a mehadrin hechsher.
They check more often and they work with the manufacturer or distributor, who is equally dedicated to kashrus, to make sure everything is done right and that if there is treyf, it is removed from the shelves and the consumer does not eat it or pay for it.
The question is on what products is this needed – apparently until now raisins were not among those products.
OT: Mishpacha used to belong to Ostreicher from New Square but he sold much of his business to an investor group that owns Manischewitz. Does anyone know who owns Mishpacha now?