Medical professionals of Reddit, what mistake have you made in your medical career that, because of the outcome, you've never forgotten? [SERIOUS]

One time I was working a side job (we call them PRN jobs, it means as needed). Well, in most nursing homes the patients wear bracelets with their name, doctors name and sometimes other bits of needed info. A patient asks for water and I follow standard protocol for administering liquids, I check the list of thin/thickened liquids in reference with their name to see what they could have. I don't know this patient because I am at a PRN job and moat cases I work a few days a month and will never see the same people ever. Look at the name on the bracelet and find out so and so can have thin liquids. Give them water and they choke really bad. I'm very qualified to handle the situation as I have done this job for many years and I am certified to administer CPR and abdominal thrusts (heimlic) if needed. A nurse comes running over and is yelling at me for administerring thin liquids to a patient on honey thick liquids (just that, the liquid is as viscous as honey. Meant to be easier to swallow if there are issues swallowing. This is very common) . I am professional so I just over look her unprofessional behavior and attend to the choking 90 year old senile woman choking uncontrollably. After I get her back to baseline and safe I go and open the can of worms that is this nurse that just scolded me for what had happened. I tell her that I am here filling in for the weekend and I did everything in the protocol and why is it that the list says they are thin liquids when they had said the patient was on thickened. The nurse says show me.. as if I am stupid. I show her. She says thats the wrong person and says I am an idiot and throws her hands up and starts screaming at me. I am a 30 year old man and shes a 50 something woman. I just sit there taking her shit rant and after she stops I tell her that there is clearly a mistake on their end, why would you have the credentials of one patient on another. She starts back up with her unprofessional rant out loud on a nursing home floor full of onlookers. So I tell her go look at that bracelet and tell me that patients name. She gwts a rude awakwning and finds the parient is labeled incorreectly. Them promptly explaims that when I am unsure I "need to ask." I tell her that I was pretty sure of what I had done and it was one of those things that is unavoidable. She again reassures me that I need to ask. So now I am supposed to ask about every person ever because anytime I work I don't know any of the patients and would have to ask about every person? She gets mad and throws her hands up and walks away. I immediately contact my supervisor and explain the situation and ask what could I have done differently and my supervisor explained I had done everything in my power and that it had been a misfortunate clerical error. Days later I was called by the corporate therapy manager and told that they investigated the building and had found a bunch of mislabeled patients and that they don't know for how long this had been and were unsure if patients had been given incorrect meds and treatments. They expressed that I had done the best that I could and appreciated my concern over the matter. I feel good about it and forget i happens. Months later that same nurse that says I need to ask, well that gem of a human being kills somebody by administerring the wrong meds to somebody. What is her exact defense...? They were labeled incorrectly. First thing I wanted to ask her was why didn't she ask somebody if she was unsure! The corporate therapy manager had done just that!he had remembered the altercation (it was jus that, an altercation) and slammed her with the same BS she says to me. TL;DR: patient chokes and wasn't my fault, not nice nurse scolds me and refuted my claim to innocence by stating, "should have asked if I was unsure." Hypocritical nurse in the future kills a patient and uses defense that I had used for which she scolded me for and said I was stupid. She caims she was unsure. She is asked, if you were unsure why didn't you ask somebody! Ironic ending for a bad human being. Sad somebody died.

/r/AskReddit Thread