Clarification about the statement - "Landowners refused to allow searchers onto their land to search for Brandon. " I see this brought up a lot and just wanted to expand on the idea. 

The land owners didn't allow family or volunteer searchers access to their land.  Law enforcement, TexSar, and Texas Rangers were allowed to conduct searches on all the land surrounding his truck,  and were even permitted to fly over and use dogs to search for him. 

There was mild interest from a cadaver dog northeast of his vehicle... but nothing came of it even after expanding the search with the dogs in that area.  

It's possible that, since many cadaver dogs are trained using pig flesh since its similar to humans, that the smell of boar produced a false hit but it's uncertain.