I agree with you to an extent but the issue isn't so much who's to blame for unexpected behaviour but rather who's responsible for fixing it. You could make all

I agree with you to an extent but the issue isn't so much who's to blame for unexpected behaviour but rather who's responsible for fixing it. You could make all kinds of reasoned arguments about who's to blame if a compiler optimisation or even outright compiler bug caused good code to behave badly under certain conditions but ultimately the end users don't care as they would still expect the application developers to fix the build scripts and/or project code regardless. To use the ships navigation system example, if you have some kind of "auto-pilot" system that would steer a ship into central London when a bad destination was set, then you'd quickly demand the authors of the auto-pilot to write exceptions for bad destinations. That's the ugly side of development; all too often us developers are having to write code to handle ugly systems. It's not fun but it's usually necessary.