09b_learner-dundercall.ipynb. Can Learner.__call__ ever return True?

In notebook 09b, in the __call__ method of Learner. If you initialise res to False and are always setting it to res and something, don’t you still get False, or None at the end of it?

I test it a little bit here by trying to skip validation and find that I cannot with the current definition.

The version in notebook 05b also appears to be the same. But other versions before that seem ok.