I think you are reading too much into it. From my experience your results are not uniform enough to warrant the guess you made or any other guess anyone would make as to what changes Panda did.
The answer is really simple - thanks to Panda Google is now broken.
If the many search examples floating around the internet (including a few good ones on this forum) are not example enough that Google is not working right since Panda, consider this experience of mine:
Less than 2 years ago I created a website to test something. This website consists of exactly 2 pages. That's it, just two pages with unique content, but nothing really special. Post-Panda this website is ranking in the top 50 for an extremely competitive phrase returning over 100 million results. How competitive? I am now getting actual traffic (although relatively small compared to the potential of page 1-2 ranking), i.e. real people visiting the website, not webmasters or bots.
How did this happen? I don't know...I've been looking into every possibility in the past few months trying to figure out how in the world did this happen and there is just no answer:
1.) the website has only two pages
2.) the layout of the website is a simple table, not even a logo :)
3.) absolutely no black-hat (or white hat) techniques
4.) there are some links to it, which I acquired mainly to ensure that the website will be found by Gbot. Compared to the competition in that niche, it's the equivalent of a drop of water in an ocean.
5.) once the website was up - nothing had been changed ever.
6.) content is unique but generic; nothing really special.
Let's face it, this website shouldn't even show in the top 1000. This tells me one thing - Google is broken and it's broken really badly. I personally am taking the "wait and see" approach with my Panda websites and believe that after the Holiday season there would be major changes by Google trying to fix the damage done by Panda. There must be, I just don't see how Google could continue serving this type of results in the future...