I have the .net of a domain framing a close friends .com of the same domain. I noticed it in Google a while ago, I cannot remember what for so I cannot get it again, but if I search for 'domain. net' it appears with the snippets and title of the 'domain .com'.
As aakk9999 has stated in the OP example when you take the Google cache from the page it has the cache of the .com and not the cache of the .net.
1. The whois is different for the two domains.
2. They are not linked in webmaster tools.
3. The only track back to me having contact to my friend is, I have 2 other domains with my whois my friend has borrowed and put G ads onto with his account.