Simultaneous ALREADY_MANAGED_BY_THIS_MANAGER and USER_PERMISSION_DENIED

[dke...@giantmedia.com]

I'm attempting to use the AdWords API with test accounts to download a report for a non-manager account using its manager account's credentials.

When attempting to do so I get an AuthorizationError.USER_PERMISSION_DENIED, which looking at the errors documentation says the manager account is likely not linked to the non-manager account.

However, when I try to link them (via the API) I get ManagedCustomerServiceError.ALREADY_MANAGED_BY_THIS_MANAGER. I'm not sure how it's possible to be in a state where I can get both of these errors simultaneously.

How do I go about resolving this so that I can download the report?