When restricting a page in confluence, you can choose any user to be able to view the page. But if a certain user is not able to see a superior page due to the restrictions of the superior page, this setting has no effect: he can not see the page although he seems to be allowed.

I see 2 possibilities:
a) the user should be able to see the page although he is "blocked" by the superior page
b) when setting restrictions for a page, confluence should only "offer" people, that whould be able to see the page depending on the restrictions of all superior pages

... I would prefer option b!