1) They didn't, and 2) Even if they had, unclear, inaccurate, or misleading information regarding Google's degree of cooperation or the mechanics of acquiring tha data in a document prepared for consumers of the data for which information on the details of collection was not essential actually makes quite a lot of sense in a highly classified program (whether its classified for appropriate, security related reasons, or for political reasons.)

Consumers of the data need to know where it comes from and its scope, they don't necessarily need to know whether its acquired through cooperation or coercion or infiltration of the providers.

This is false. The NSA did not list Google as a partner. Reporters may have, which is different from what the leaked slides actually say.