Can a nurse refuse to disperse a patient's medication due to vomiting?

30 minute window is very short. I was outraged when my Mother and I went out for breakfast when she was in Personal Care and the night nurse who worked daylight one day a week would not give Mother her medicines because we went out to breakfast but would soon be back. The Nurse was not in the Nurses Room when we left so we left the message with the Nurses Aid. The Nurse was really angry at me because I caught her giving Mother the wrong eye drop in the am and conversely Mother was getting only 1 eyedrop prescription instead of 2 , the 5 nights a week she worked the evening shift.  Mother was having hallucinations, Charles Bonnet Syndrom and had we not  gone to a Specialist who wrote a letter asking for an intervention with me giving mother her eyedrops,   we might not have ever gotten Mother out of there.  The facility and the Nurse retaliated against me.  The Nurse in mother's situation told me we missed the window.  While the Nurse for your Mother had an excuse, the fact that she said the window was only 1/2 hour seems fishy.