EMD slashed... Well I tell you what guys. One of my sites which is pretty old and NOT EMD has been #1 for very competitive keyword for several years. Guess what happened? During the latest G update my site was pushed down to #7 and outranked by 2 EMD sites that were nowhere to be seen before! This is insane. Well, go figure. I for one would be quite happy if the update actually worked for all EMDs.
Your site was probably impacted by Panda, which ran around the same time (definitely the same day). The update is just for low-quality content EMDs, i.e. ones relying on the keyword in the domain rather than the site's content.
No. Just fix the problems with your site's contents/links and then wait for the next EMD update. See: The EMD Update: Like Panda & Penguin, Expect Further Refreshes To Come