Contradicting Instructor Information?

Hello! I just had an odd experience at lab today- now, I understand in nursing school, instructors usually have their own way of doing things that differ from teacher to teacher. However, we witnessed two instructors today having a debate in front of us with no apparent compromise on the question. (This happened in class, while we were divided up into our clinical groups, reviewing medication administration). One student asked a instructor passing by our group about her handout and administering 1ml into the deltoid vs 2ml, which was what the book said. That instructor sternly said that only 1ml should EVER go into the deltoid, while OUR instructor defended that the book claims 2ml can be given in the deltoid. The other instructor claims it must have been a misprint in the book- OUR instructor refuted that at her clinical site, they do give 2ml injections into the deltoid. It was confusing, because we weren't sure who to follow. We were told to just follow 1ml for the exam- but I'm curious now. In the event something like this happens again, how are we the students, supposed to address this? Do 1ml with one instructor and 2ml with another? I understand each facility has their own protocol.. but I feel as though this should be something standardized?