In all honesty, things like this are a minor part of SEO. The main areas in SEO you should aim to tackle are writing mega ultra high-quality content and obtaining backlinks to as many pages on your site as you can. Backlinks = votes, and votes = attention. Attention = traffic. Search engines follow people, not the other way around.
Work on content and backlinks and forget about this problem. Of course, you could always work on making sure you don't do this in future, but it really isn't that important.