We went to the lounge car to play a card game and got shoo'd out because he was closing down. We didn't want anything. Just wanted to sit at the big table, but nope, not allowed.
Assuming you were in the cafe/dinette/club dinette car (single level trains don't have a lounge car) and didn't actually land in the diner, this was pretty s...... of the attendant. I don't know whether s/he was acting according to the rules or not, but attendants have a tendency to do this within x hours of the destination.