That’s why monitoring, fail-safe power offs and redundant systems are important. E.g. even at the complete failure of a CAT scanner’s higher level control (which let’s say would run on an embedded linux kernel), the system would safely stop the radiation and power off, without any instructions from an OS. Here, an inconsistent state from the OS is actually more dangerous than stopping in the middle (e.g. the OS stucks and the same, high energy radiation is continuously being released)