Here is a strange one for you. We have a server with multiple VHOSTS that include both SSL and Non-SSL domains.
Domain1 is SSL enabled, while Domain2 doesn't have SSL.
Since all these domains are hosted on the same IP, apache would respond to httpS requests on domain2 by loading the first SSL enabled vhost, so basically if you went to httpS :// domain2 browser would warn you against an SSL mismatch which would require a user to click on advanced settings prior to seeing the content of Domain1 (the first SSL domain of Apache)
1) If chrome is smart enough to understand there is SSL mismatch, why the heck would Google still index content of Domain1 under https://domain2.com
2) We have since fixed the issue by a putting a re-write that shows 404 for all pages of httpS // domain2.com, We have also used Google Webmaster tools to remove all entries of httpS // domain2.com, however, these keep coming back every 4-6 weeks! I went as far as using Google's fetch URL tool to make sure httpS // domain2.com results into 404 from their point of view and indeed it does.
How the heck is Google still finding content of Domain1 under httpS // Domain2.com? Are they relying on Caches even after a removal request?
All I can think is that Google has the content cached locally and they keep using that content to create indexes again; meaning once we manually request removal of content, they do not crawl the site to re-create that index but they rely on their own local cached copy.