I actually doubt its an accident. One of the problems you have to deal with when manufacturing in China is "substitutions". In China, the contract you sign is j

I actually doubt its an accident. One of the problems you have to deal with when manufacturing in China is "substitutions". In China, the contract you sign is just a place to start negotiations and the prototype that they first present to you is considered a loose guide to how they will build the actual product. As time wears on and numbers increase, you'll find all sorts of tweaks to save a penny or two showing up on your latest batches. They don't try to make your product non-functional, but they might make a mistake on a substitution going after that 1/10th of a penny.