I know of one hospital, more like an elderly care unit, where the nurses feely told us that the pudding fools were not vegetarian despite the printed sheet for ordering each meal stating that they were.
I tried to raise this with the catering firm, but they were not interested, and I had other things to attend to.
I think this sort of thing is commonplace. patients/families are too worried about their own situation to make a fuss, if they try to speak to someone its usually a catering assistant who barely speaks English, and has no influence on the matter.
nursing staff are v busy and otherwise occupied.
no one has time to pursue it.
we aonly found out when the nurse offered us some yogurts left in the fridge by a hindu family as they could not eat the supplied puddings. it was the mis-labelling that bothered me. no one seemed to care. very small potatoes, excuse the pun, compared with other concerns.