How do you know its the former and not the other. Google's experiment doesn't discriminate between the two.
The key question is whether they have special rules in place for google. I am indeed presuming that if i were using the same tools google did on my personal website, i would not achieve the same result.
Bing probably has a ranking algorithm saying that links from google.com search pages have x weight and links from facebook profiles are valued at some other value etc.
They are also susceptible to Google "poisoning" the well, by creating a bot-net to provide fake data to Bing.
Was it just the top result that was copied or were more of the results copied as well?
It would be interesting to see where the law comes down on tracking clicks for a competitive advantage. I doubt anything will get past handbags at dawn, as it could draw attention to click tracking on ads, and no-one want that.