Inconsistent behaviour static assert directly or via mixin?

[DLearner]

Consider:
```
void main() {

    string Foo() {
       if (__ctfe) {

          return `static assert(false, "Indirect");`;
       } else {
          return ``;
       }
    }

//   static assert(false, "Direct");

    mixin(Foo());
}

```
If run, produces 'Indirect' message _and nothing else_.

Now remove the '//', get 'Direct' message _and code dump_.

Inconsistent behaviour?