Your comment makes a lot of sense!
My bet is that Probe started the discussion and Noront has so much on their plate that they were only interested in a 'Great' deal and Probe also wanted a 'Great' deal. Parties likely way too far apart to agree.
I'd be a bit nervous owning Probe because Noront does have the best feel for Geology in the area and certainly for McFauld Lake section. If they really thought Probe had a nice deposit on their claims then a deal would likely have been done.
My personal feeling is that Noront's Geologists know better than Probe's what exploration is likely to turn up. Oh yes, they also know better what the total cost to find out would be.