One thing wrong with your logic is that this sort of stuff does happen, and Google's algorithm does let cracks like this through.
This site has moved. Please go to the new site (no href - don't let google see) www.example.com.
An automatic redirect (w/ javascript) would probably be the best way to go, with a message explaining the move while the reader waits the 5 seconds for the redirect to take effect. (Google doesn't evaluate javascript, to my knowledge.)