I complained in a review that I received a China region code camera and the seller asked Amazon to remove that feedback. So take the review with a grain of salt. Also, different sellers share the same review pool as they use the same product ID. so you never know. I believe the seller was hdsecuritystore and was 'fulfilled by Amazon'.
A complaint in a review without going thru the normal Amazon reporting procedure can end up getting your review removed, as you experienced. The reviews are not what you use to report abuse by a seller, you must use the normal Amazon complaint procedure FIRST - then do your review AFTER Amazon does its investigation. Amazon will NOT remove a review that is backed up by an Amazon complaint. Sellers know Amazon's rules and will leverage them against you if they can, they prey on buyers lack of knowledge on Amazons procedures.
The review pool sharing is correct, this is a good thing because buyers want information on the item more than the seller of the item (there is a seperate review section for sellers). The idea is to find a review where a purchaser says they received an English version from company "X", and those that say they got a Chinese version from company "Y", avoid the "Y" companies.
As mentioned in my previous post "fullfilled by Amazon" should not give you a fuzzy warm feeling when purchasing - it just means the item is already in Amazons hand and will be shipped to you from Amazon. Now to be sure technically Amazon is suposed to review an item for correctness before accepting it for fullfillment by Amazon, however, they do not inspect all items given to them for sale - usually just a sample item sent by the company. The company could have sent them an English one to review but after approval sent in Chinese versions for sale. It could also be that the reviewers of the product being submitted don't have the expertise to know a Chinese version from an English version - duno. Amazon relies on customers (even more so now that they have expanded greatly) to point these things out to them.
Amazon will remove a seller and their items for sale if they get too many complaints (I've even seen them remove a company for one complaint - depends on the egregiousness of the complaint).
Still the best way is to contact the seller BEFORE you buy any item on Amazon if you have any doubt on what you may receive. Of course you are still protected by Amazons buyers protection, so if you do get the wrong thing all you should be out is time (ya I know - time is money).