I am a relatively new nurse, so, at this time, I would also say that I wouldn't want to be the one to administer meds without an order.
Is your unit manager an RN? If so, then, I would have told her to go ahead and give it, since she is the higher licensed person than I. I suspect that she was more upset about the fall, than the reason behind it (not that this fool is correct, by any means). It seems to me that she would rather that YOU ride it if the meds were administered without an order rather than HER. Now, what if the doctor wanted to order something else besides what you expected, and the effects were compounded?? Maybe the next time, she would have fallen because she was trying to run to the bathroom to avoid a nasty code brown!!
I have been in a few situations that were dicey...in my hospital, LPNs cannot take verbal or telephone orders. Yet, once I had a patient who was to go to the emergency room for chest pains. Resident orders 81mg of aspirin, we had 325 mg available. Because of the chest pains, and knowing that aspirin can help if it is an impending MI, I felt to give it, but went to the resident first to tell him what was available and asked if he wanted me to administer that instead. He says 'yes' and then, I told him that he must immediately write me an order. He was on his way to meet the preceptor, so, I wrote a note and taped it to his computer screen to remind him. Something told me not to document just yet that I administered it, and then, the resident disappeared for the rest of the day (shift was over in my clinic) and he did not change the order.
I went to the attending and explained to her what happened and she covered the order for me and the patient was transported safely to the ER. I then documented what was administered. But, that was not comfortable for me. Next time, I will tell the doctor that I will not administer anything without an order...period. Can't trust them. I think you did the right thing.