It's a good lesson because this kind of thing is going to happen ALL THE TIME. On every level. When you are a nurse, you will have similar interactions with providers, who may have similar interactions with their attendings, or with the PCP or specialist, etc, etc, etc.
Communication is a constant flow. Some people are great at it, some people struggle, most of us are in between--and we all vary in our own abilities depending on the day. In the hospital, everything that happens to patients from admission to discharge (and beyond) depends on communication and collaboration.
My approach is to try to start my day with the assumption that everyone I encounter has a predictable, if not similar, goal. Every time I interact with a patient or colleague, I try to make sure I am understanding where they are coming from (because I will act on those impressions, so I don't want to be wrong). Sometimes I might not get that clarity very easily--for example, in my role as hospitalist NP, I sometimes find myself between multiple consultants who aren't in agreement about something, and my job is to sort through that information and come up with a plan for a patient. When I am feeling challenged by this I need to take a step back and re-work the problem. (there are clues that I need to re-direct myself--if I find myself, for example, asking a question more than once or twice, I am "clued in" that I need to approach something differently)
In your case, you absolutely have the ability to take ownership in your situation--when you are talking to the patient for the second time, for example, that is a clue that you are missing necessary data and you need to take a step back, look at the information that you have (a patient is asking for something, the nurse isn't providing it), and the information that you DON'T have (why isn't the nurse giving the patient what he is asking for).
Then you have your question. You ask the nurse--if she doesn't think that you need to know, then you can tell her that she needs to speak with the patient. If she tells you and you feel comfortable relaying it to the patient, then you can solve it that way. If you don't feel comfortable telling the patient, you make a plan with the nurse so that you can tell the patient that his nurse will explain shortly.
The most unpleasant experience is when you feel you are not on the same page as the team you are working with, and you are confronted with questions that you can't answer without making someone look bad. If you get to that point again (we all do even when we try to avoid it), apologize, sincerely, to the patient "I just don't know the answer right now, I think you need to speak with your nurse, I will go get her for you, please understand of it takes a few minutes". Or something. Then tell the nurse "please speak with Mr. Patient as soon as you can, as I can't help him with his current request"
Or something. Keep the flow, ask questions, take control.