Dean Zhu put away the files, "I won't keep it from you. The gastric bleeding patient you operated on last time, it wasn't Zhao Mengmeng who mistakenly administered the wrong medication, it was Wei Jiani. She genuinely thought nobody knew about what she had done. I only found out after a patient told me. The patient said he was in the restroom that day and saw Wei Jiani replace Zhao Mengmeng's medicine, and not long after, the mistake happened."
This patient didn't want to bring this up initially, but the sight of the nurse being chastised and apologizing made him feel guilty. Although he rather liked the intern Wei Jiani, he eventually decided to speak up about what he saw.
It's crucial that the innocent be exonerated, and those at fault mustn't go unpunished. Otherwise, he asked himself, what justice is there remnant in this world? Where is the truth?
Thus, he informed Dean Zhu of the incident when he was discharged.