after I did some research on the subject, I found that Windows Live stopped providing email addresses for a user's contacts through its API. Instead, they provide the email hashes.
I did a little more research, and i found many websites being able to retrieve the contact list for a user and displaying it (with emails, not hashes) but the difference is that i don't think they are using oAuth since to retrieve the emails, the user must provide his email/password.
I need to implement importing a user's contact list on my site and i see no workaround to doing it using oAuth REST requests through Live's API (granted that i was being able to get the access token and make other REST requests).
If not using oAuth, what are other ways of getting a Windows Live/Hotmail contact list?
I ended up using Windows Live ID's Delegated Authentication. Even tho it's deprecated it'll have to do until i find a more effective solution.