fathom - 1:06 pm on Mar 26, 2013 (gmt 0)
only has 7 backlinks to their entire domain
Just because you only see 7 backlinks doesn't mean those are the only backlinks the domain has.
Much like Google prevents you from seeing queries typed in by those logged into their Google Account... all domain owners can prevent you from scanning the backlinks they provide.
If you disallow a link checker from crawling... guess what?