The Causality episode on this is really good: <a href="https://engineered.network/causality/episode-39-therac-25/" rel="nofollow noreferrer">https://engineered.network/causality/episode-39-therac-25/</a>
> 1986, the programmer left AECL. In a lawsuit, lawyers could not identify the programmer or learn about his qualification and experience.<p>I find this hard to believe: how? Are there no records?<p>Edit: apparently the identity is known, but the lawsuit was settled before a deposition was required. Also:<p><a href="https://www.reddit.com/r/programming/comments/mzht1/comment/c35aobl/" rel="nofollow noreferrer">https://www.reddit.com/r/programming/comments/mzht1/comment/...</a>
So they took components from a previous system, didn't test properly on the new system and today we inherit a whole lot of regulation for medical equipment because of this. Not that it's a bad thing that we ensure proper testing has occurred but there are so many cases where legally this applies even if it's very peripheral (like say a UI change in a menu item of something not related to medical equipment but is never the less under compliance)