I think a point has been missed in recent posts:
Even if the people offering the tea and biscuits did ask if the patients had special dietary needs, and were told by the patient that they were diabetic, they would still offer the tea and biscuits. Because according to the NHS eat well guide, tea and biscuits are fine. One of the pictures of food types in the eat well diagram looks very like a packet of biscuits to me. It's under the pictures of bread, cereal and potatoes.
The elephant in the room, and the really burning question that needs answering, is whether the digestives that
@Catlady19 was offered were plain or chocolate. If they were plain, then clearly she was being treated as a second-rate citizen as everyone knows chocolate are better.