Sitting spot #1 for "SEO"

If you don't believe me, take a screenshot of the top 10 for phrases like "SEO Company" and "SEO Services" every 6 months. By the third time around you'll see what I'm talking about. I won't name any names, but the site that ranked #1 for "SEO Company" from about 2010 to 2011 (consistently) is now completely obliterated from the SERPs. Their site hasn't changed whatsoever.
Out of curiosity, have they changed much of the content on their homepage since then? I'd check, but unfortunately that's not one of the keywords I have historical data on (for the US anyways)