Her account of her behavior sounds a little saccharine, so I don't entirely believe her. That being said, when working registers (not in a pharmacy, though) I recognized that you need to tolerate people on the phone and you can generally do your job either way. So it really depends on whether any interaction was actually needed. If it was simply ringing up a transaction that didn't involve asking any questions, she probably should have just done that, so I side with the customer. If she had to ask questions for certain information, I would side with the pharmacist.
Without the other side of the story, it's hard to say.