I think it is appropriate to discuss this with your instructor -- not to necessarily take any action, but to explore your feelings.
While it is not a good idea to just stand by and let something happen that you think is wrong, I'm not convinced the patient was significantly harmed. Your primary responsibility as a student is to learn, especially in an OR environment where you are basically just observing (as opposed to being assigned a patient on the floor where you are taking on the duties of a nurse). It sounds like it was a fruitful experience because it gave you a lot to think about. I guess what I am trying to say is, while it's admirable that you feel so responsible to the patients, you shouldn't feel guilty in this circumstance. You are just a student...
Now where were the nurses when this happened?
http://forums.obgyn.net/ob-gyn-l/OBGYNL.0001/0456.html