ElReg cache flush
"We therefore asked Google if it offers service levels for requests to flush its cache. The company told us it wouldn't comment on an individual case [...] Neither really explains how it would respond to a request to remove data from its cache."
well, D'OH... you basically asked if water is wet.
go to the link where they told you to go, you have to verify ownership of the site and then you can dig in settings to flush cache and pretty much nuke everything related to that site's presence on Google.
Bing and the other major search engines have similar options, so it's a bit of a whack-a-mole to do that with various search engine caches.
The site owner can also add a robots.txt to the website with: