I think there is a bug when you change the parent page and comes back to the old parent again. This is producing a indefinite redirection.
For example, i have a history page
The page has a parent page "about" so the url is /about/history/ if i change the parent page to "contact" the new page url will be /contact/history/ and it will produce an automatic redirect from /about/history/ to /contact/history/.
Now, if i edit the history page and put "about" as parent again. it will produce an automatic redirect from /contact/history/ to /about/history/.
So if you see every time you access to one of them it will redirect to the other one and so on.
Maybe a validation to avoid this kind of situations would help.