Order Processing Timeline Question?

I have a question about timelines for processing an order after a hospital discharge.

I previously worked in an adolescent residential treatment facility. We had a patient to to the hospital for psychiatric stabilization for 4 days. We knew the patient would return on the day they came back, but they came back after-hours (nurses are m-f days and on-call but not required to go in when on call). Resident came back in the evening, med orders were processed early the next morning (about 12 hours after they returned).

The resident had a medication discontinued while at the hospital, they got one dose of this D/C med in the AM. No adverse affects were reported, no medical intervention was needed. I got fired for this. I cannot collect unemployment either because they claim that this was such a serious med error. By definition in statues, it is not. Would I do things differently in the future--absolutely! Mostly just beating myself up about this because there was no malicious intent--but that's how my employer is posing it

Here's a twist...the other nurse I work with actually took report a the end of her shift from the hospital--so she knew what medication was being added and which one was discontinued. I to this day don't even have that knowledge. She didn't pull the med that would be D/C'd. I got the heat for it because I am there an hour later than her and I was on call that evening.

Thoughts/advice? I have heard that there is a 24 hour window to process orders, but I can't find anything about that anywhere...my unemployment appeal is next week...