BB, "I couldn’t imagine how an unidentified third-party might make such a proposal about using someone else’s property"

I can and it could have been:

"Sibley Basin Group recommended that further drilling be done"

Not just using someone's property but paying for doing so, rent/lease/cooperation.

During any assesment or study a number of alternatives are usually proposed and the receiving company takes any of these and runs with them. The fact that they do not mention Noront then I conclude that it was probably not Noront and that KWG do not want to name the source of that idea.

It is possible that Noront not only was not contacted before hand but knew nothing before the idea was stated to the public, however I do think that it must have been mentioned to Noront at least unofficially, say telephone converastion.

Just my guess.