Zivush - 6:58 pm on Dec 25, 2012 (gmt 0)
You are getting into semantics.
You can make some here and there "errors" and get under the radar. It's not a math science.
Some errors (like the one you've mentioned) may be considered minor or even super-minor.
On the other hand, I think that even if you clean your site from over-optimization errors and other internal linking mistakes, it might not help.
Some other factors may get your site into panda or penguin which aren't SEO related.
for example, focus on giving the best user experience to users.