What probably has escaped you is that dumplings with pesticides have been found in China, as reported by Globaltalk 21. Last winter several people got sick from eating imported frozen dumplings from China, and it turned out the dumplings had been deliberately laced with a banned pesticide; an overview is available here. The investigation quickly turned acrimonious with Japanese and Chinese officials claiming the poisoning could not have occurred in their own country.
So, pesticide-laced dumplings have been found in China, raising the probability that the poison indeed did originate in China rather than being added after the dumplings were imported into Japan. Jun Okumura above sees an attempt to discredit or embarrass China by having this information leaked right before the Olympics. To be sure, there's lots of mutual animosity between the countries; I agree with him that there's plenty of people here that would love to discredit China in any way they can.
I disagree with him that this is the intent of releasing this news. A week ago, or two weeks would have been understandable and effective. But releasing such news - or any news - just hours before the start of the Olympics is pretty much the worst thing you can do; if anything this is the perfect time to bury news, not highlight it. During the next two weeks, much of the world is going to ignore the recession; the two wars in Afghanistan and Iraq; the US presidential campaign; and the cost of oil. Some trivial thing like a few poisoned dumplings are not even going to register with much of the people. If it really is an attempt to embarrass China, it is a singularly incompetent one:
- Hey, there's poison in these dumplings here in China!
- Shhh, Ernesto Ramirez is about to jump 4.55!
- Um, ok, good for him, but we found actual poison in these dumplings and...
- Elena Vladivostoka just got 9.24 in the Womens Alternative Combination!! Do you understand what this MEANS?!- Well, no, not really but look, about these dump-
- Neither do I!! ISN'T THIS EXCITING?!?!?!
- Hello? Dumplings? Poison?
- GO TEAM!! GO TEAM!!