if they own the account, they have full access - if you read the details, especially #1 and #4, you'll see they're talking about agencies that "sell" adwords. if the client owns the account, you're not selling adwords.
G doesn't want someone lying to their clients about how they are using AdWords, or what the costs are - if the client owns the account, they can see everything and they are most often billed directly.
read the example about keywords, they're worried you'll report adwords data bundled with other platforms - they require you to unbundle - again, to make sure the client "sees" the value and cost of AdWords clearly.
so i am sure, but who knows, crazier policy interpretations have happened to me (though not at G). so i'd advise you to contact G support directly, not just take my word for it.
the disclosure requirements for 3rd parties:
"Not sharing the cost and performance of AdWords campaigns: You have a right to know, at a minimum, the number of clicks, impressions, and cost of your AdWords advertising."
so even if i am wrong, and managing adwords counts as "selling" adwords, if the client owns the account, the have (and control others) access - so they have the access to the info "sellers" are required to provide to them.
"Google third parties who provide any level of cost and performance reporting today should make AdWords cost and performance information easily accessible to their advertiser clients and available at the same level of detail as other reporting information."
if it's their account, i'd call that easily accessible.