Chaos ensued after a 7.8-magnitude earthquake hit Nepal on April 25, ultimately claiming more than 7,500 people’s lives. Neurosurgeon and CNN’s Chief Medical Correspondent Sanjay Gupta was reporting live from the scene as he performed life-saving surgery on an 8-year-old girl who had barely survived a house’s collapse. But as he discovered months later, he had never operated on her at all. Instead, he cut into the skull of another girl.

“I hate mistakes. I really hate them,” Gupta told The Daily Beast. “I take this very seriously. We’re going to learn from it. I’m going to continue to dissect it. I’ve thought about nothing else, frankly, since they first flagged this for me on Tuesday, and I’m going through everything… If there’s a lesson to be learned, I’ll certainly share that.”

CNN’s team arrived in Nepal’s capital, Kathmandu, two days after the initial earthquake, and Gupta was sent into the heart of an overwhelmed Bir Hospital. When he arrived, doctors presented him two CAT scans: one of a 14-year-old Sandhya Chalise and another of an 8-year-old Salina Dahal. Both patients had epidural hematomas on the right side of their brains, however, one was in a more dire state than the other.

The hospital was in desperate need of staff physicians and Gupta said once the hospital recognized him from television they asked if he could assist in a craniotomy. As a neurosurgeon, 45-year-old Gupta was familiar with the procedure, and he proceeded to remove part of the girl’s bone from the skull wielding a drill and string saw.

“When I went into the operating room, the surgeons came and grabbed me, they said they were not going to start the case until I was in the operating room — the patient was already draped,” Gupta recalled. “So when you walk into a situation like that, the best way I can describe it is all you really see is the top of the head.”

Without questioning the identity of the head, Gupta cut into the bone to remove a blood clot, which relieved swelling in the brain caused by blunt trauma. The entire procedure was reported on CNN, with a surgical scrub-clad Gupta declaring to his audience that the surgery was a success. Without the emergency surgery, Gupta said, she would’ve had permanent brain damage or died.

But it wasn’t Salina he had operated on — instead it was Sandhya. When the story first broke on CNN’s program “New Day” on Wednesday morning, co-host Chris Cuomo interviewed Gupta on the medical mix up.

“What has been flagged for us now, Chris, is in fact that the patient that I operated on may not have been this 8-year-old girl, but rather a 14-year-old girl in that same hospital during that immediate aftermath of the earthquake,” Gupta said in the segment.

In the aftermath of the announcement, Gupta has agreed to interview after interview with news outlets. Whether it is to set the record straight or because he feels that as a hybrid doctor-journalist he owes it to his career, he has been publicly retracing his steps as more details unfold. Salina did eventually get the care she needed that day, but unfortunately, it was as the price of both erroneous reporting and medical malpractice.

“A good surgeon knows the identity of the patient he’s operating on,” said Ganesh Bahadur Gurung, the vice chancellor Nepal’s National Academy of Medical Science, which runs Bir Hospital. “[Gupta] is not a surgeon, he is a butcher.”