I don't see anything on that page with gives you, the OSI, the legal right to declare things as being opensource or not. You categorically stated it wasn't opensource. Had you stated that in your opinion it wasn't opensource it would be different.
Sorry, who said anything about a "legal" right?
Maybe you're reading too much into the OP's comment.
Mongo submitted an application at OSI, and OSI is saying that currently, they don't consider Mongo open-source, based on their own definition.
Perhaps you're just confused?