You say that like humans don't err, either though malice or madness or mistake.
https://www.npr.org/2019/10/02/766403612/doctor-gets-40-year...
https://edition.cnn.com/2021/05/18/us/virginia-former-ob-gyn...
https://www.npr.org/sections/health-shots/2022/03/25/1088902...
https://www.theguardian.com/uk-news/2023/aug/22/lucy-letby-w...
https://en.wikipedia.org/wiki/Harold_Shipman
https://www.nationalgeographic.com/history/article/handwashi...
https://en.wikipedia.org/wiki/Andrew_Wakefield