Somebody's hacked into my car (near future)

This new trend of driverless cars and their ongoing legalization process keep me wondering who would be responsible when the driverless cars start causing human deaths? After all, the core of this technology is the software, a very complex set of software, the same software which tend to have bugs and security vulnerabilities. What if somebody hacks into (remotely or locally, doesn't matter) my future car and program it to kill somebody then replace back the changed software with the original? Flawless murder?