Yeah, I suppose for the end user I doesn't matter if program stopped working because of segmentation fault or a panic. Though, if one were to choose on of those

Yeah, I suppose for the end user I doesn't matter if program stopped working because of segmentation fault or a panic. Though, if one were to choose on of those issues, then obviously runtime errors are preferable over memory-safety problems that might lead to an arbitrary code execution. BTW, in Java data races do not cause undefined-behaviour. In fact there is no undefined behaviour in Java at all (as specified at least, in practice as you and many others have observed things may work quite differently).