It's not that he wouldn't be granted full access, more that a non exec wouldn't expect it. Their role is generally to challenge strategy rather than check if the milk bill has been paid.
He appears to be well qualified but I question his sanity. Bear in mind this is a non executive appointment. That means he will not necessarily be privy to the operational minutiae.
There isn't even anyone who fits that descrioption as a manager given Di Matteo was in charge for the Champions' League. Or do you actually mean Di Matteo -who is assoiated with (not) Abdallah's agency?