I believe all Small D 2001 panda coins are genuine. It's not possible to stamp D on a regular 2001 panda so to creat Small D. Silver is very soft, such stamp process will break the coin or will at least shows uneven on the reverse side, furthermore, if you check NGC census or studyig all pix of all the small D found till now, D is at exactly the same place at each Small D coin, I don't believe fake makers can manage it unless they have a real die, in other words, they were not able to stamp D at the same place at every coin. Furthermore, if they want to make big money, why they didn't create some "double D" or other more different D styles on regular no D panda to rip off? Only this small D variety? So the only explanation for this small D coin is that they are genuine coins, I believe Shenzhen Guoboa Mint was short of experience back on 2001, somehow they broke the large D die and had to use a new die to make coins, this new die's D was smaller than the old die and its D position was also not exactly the same as the old die, by using this new die, small D coins were made, and that's the only fact.
Zhao Yan Sheng wrote that he has contacted the Mint people for an investigation... But how can he contact all workers and management people at that time? Back to 2000 and 2001?? It's absolutely not possible, people on board and quit job often, he cannot find all people related to this coin back to 15 years ago, so he is telling a lie and the question is what else in his article is true.