Okay, another lame-brained situation which you've by now come to expect to hear from me. :)
A new site I started working on this week. It is a syndicated author's column. We noticed they weren't ranking highest for their own column title on their own site, but some of their syndicators WERE even though the main site has been around for 10+ years with lots of backlinks and their syndicators were only a couple years at most.
After a few minutes of looking around we realized there was a minor, practically unnoticeable, misspelling in the HTML title tag of every weekly column page going back 10 years! The column title is the first 20 chars of each title and the rest of the title describes the subject of that week's column. If you search with the misspelled version it comes up #1 everywhere, but only about 7th if you search on the correct spelling.
We can easily go in with a global search/replace and change all 1000 or so of them in seconds, but will G have an issue with it when it suddenly sees all these title keywords change?