I see a minor flaw with the experiment... if I understood the article correctly:
Google makes a bogus search term to return a list of results the first of which is an unrelated page (the "honeypot"). Engineers start clicking on that link and in a couple of weeks Bing also starts reporting that link as the top result for the bogus search. Bing is exploiting Google's rank, QED.
Here's the rub... what would have happened if Google had made the honeypot appear *last* on the result page and had its engineers click on that anyway? I suspect that Bing would have still reported that link as the top result. The ranking would be totally different, and it would be really hard to contend that Bing is exploiting Google's rank.
My wild (really wild) guess is that Bing is just collecting the URLs users navigate to and feed those to their indexer, exploiting user's judgment to find obscure relations between search terms and web sites (Google's redirection would make this pretty efficient). The fact that Google is the most popular search engine by a mile, and the fact that the top search result gets an inordinate amount of click love, would make Bing's results more similar to Google's than one might expect, but if my guess is correct, it would be just be a welcome (but not necessarily intentional, or malicious) side effect.
The biggest flaw in the experiment is that Google set up one "honeypot" page for each bogus search. Therefore, Google's experimental search results each yielded one page that was both the "top ranked" and "bottom ranked". There WAS NO OTHER LINK to click. Therefore, when Bing's search turned up the one link, the only thing Google engineers proved is that Bing's optimization methodology worked.
There are two important aspects of search results: the number results returned AND the rankings of each result. Google engineers took the trivial case and declared a correlation.
These guys must have gotten Fs on all the labs they did in their undergraduate work.