Wasted time

On my recent self directed placement i was required to create 2 educational pamphlets for amputee patients. The pamphlets required me to do a lot of research but i found the topic interesting and i learnt a lot while making the pamphlets.

The problem i encountered was that in the first week of my placement when i was trying to research the topic thoroughly i was told by my supervisor that i was required to attend the facility every day of the first week for at least a few hours.
I thought this seemed ok because i needed to learn about amputee patients and how their treatment works. The only problem was that i needed to spend a lot of time at home researching the topic and i didnt want to be at the facility wasting time.

I was also under the assumption that we werent meant to to be treating patients during our self directed prac (unless it was directly related to our self directed prac). A situation arose on the second day of the prac when after spending some time talking to some patients my supervisor asked me to take another patient for a walk. I agreed but then quickly found out that this patient was irrelevant to the pamphlets i was making. I couldnt leave the patient because they needed someone with them and so i continued assisting the patient while they walked around the building.

The walk took over half an hour and i was quite annoyed with the time i had wasted. I wasnt annoyed at the patient, just at my supervisor for getting me to do things i wasnt there to do. I thought about discussing the issue with my supervisor but decided against it because i thought it would be better to finish my self directed prac without upsetting anyone.

I think as a student i probably made the right move by not discussing it with my supervisor because its never really in your best interest to upset someone when you are a student. Has anyone had a similar situation or does anyone have any thoughts to add?