Yeah, I get the sentiment that you can't avoid bugs and I think to an extent they are inevitable at a certain point. But something like this is just negligence.
My company isn't medical or anything life threatening if something goes wrong, but a bug could cost someone a nice heap of money, in turn costing us a nice heap of money. So we have a rule to treat and test our software as if it were used in the medical industry. Although it seems like we should be aiming for a higher standard at this point.