Google errors as an opportunity
It is well known that whenever google repairs its database or network it takes months or long, in the mean time it does not keep itself on top position and so most of the sites that earlier have good page rank in google, are then nowhere found.
Generally speaking, such kind of loss of website does not always give a bad impact you can consider it as an opportunity. Because once you have lost the traffic you are required to rewrite the URLs. And to rewrite a URL is itself a big opportunity to make website more search engine friendly.
But most of the time the redirecting job of the old URLs creates problem and that time “pushing lost data” procedure can be a good benefit. Thereafter as Google returns along with complete indexing, it tends as a new URL.