It is a different thing. Non determinism is different to undefined behaviour. Undefined behaviour can cause miscompiles which can break the expected logic of a

It is a different thing. Non determinism is different to undefined behaviour. Undefined behaviour can cause miscompiles which can break the expected logic of a program. In the worse case, maybe the compiler optimises away your password validation because it has decided that the failure branch is undefined behaviour. Non determinism can lead to logic bugs, but it can't magically introduce new logic into the program like UB can as part of optimising