The chance of either of those URLs being present on a site would have to be miniscule. Most likely they followed some outdated link somewhere.
- someone having the domain before you
- script kiddies machine-generating links to pages on random domains so Google finds exploitable targets for them
Google is not randomly looking for pages - that's brute-forcing a site map and it's utterly, impossibly inefficient even to supplement what they find crawling around.