@Serene,
We have had that happen especially since pharmacists are used to eRx. Nothing against your post, but the pharmacists really ought to check all three possibilities.
I also think a lot of pharmacies won't fill the script until the patient arrives. I think it depends on the format of the script. Even putting a label on a box of Triamcinolone 0.1% means tearing it off. And, if they don't show up, they have done the extra work.