Nice catch, I didn't notice that at all when I saw their numbers originally, though the fact that the Tin and Silver numbers are a multiple of the Gold numbers should be a big tip off.
One thing I'd like to know more about is how environmentally sensitive this processing actually is. My guess is that this takes place somewhere where they do a lot of other extraction from electronics components as well, probably China, and those processes are not necessarily too environmentally friendly. Extracting Gold, Tin, Copper, Silver, etc. often involves the use of strong acids, and the use of many other potentially hazardous chemicals. If care is taken it can be a relatively clean process, but if care is not taken it's pretty easy to damage the environment by just dumping the waste byproducts.
Example: https://en.wikipedia.org/wiki/Electronic_waste_in_Guiyu