From the Hacker News thread
A clearer description of the bug is here: twitter.com/Tims_Pants/status/173051513… It's wild that this sort of bug got through testing. As a diabetic it feels like our insulin pump software is very conservative and lacking in features especially compared to what some of the "closed loop" things would like to do. That seems reasonable if the manufacturers are having to do lots of safety testing. But if bugs like this are getting through then the testing obviously isn't anywhere near as robust as we'd like.