Unless I'm mistaken, Lesson 9.3 is the first instance that the potential form conjugation is explained. However, because the lesson is using informal speech, the ichidan verb conjugation structure that is used is the colloquial V-stem + れる instead of the standard form V-stem + られる。
My two cents would be to either add the standard form かりられるto this lesson or indicate that かりれる is informal potential form conjugation.
My two cents would be to either add the standard form かりられるto this lesson or indicate that かりれる is informal potential form conjugation.