I asked the store owner about that and he said that his scorpions aren't generaly overfed. I've known him for several years and have seen many scorps go by and know this to be the case. None of the other scorps looked this big, that's for sure. Plus, there is the consideration that he uses crickets for feed and this is a substantialy sized scorp. It is the little ones that can trick you after having eaten a big cricket.
Depends on how you look at it. Common knowledge (i.e. what I've just heard around) has it that the emp is the heaviest scorp and that either one of the Hadogenes (flat-rocks) or Heterometrus swammerdami have the longest record. I don't know what the actual scientific answer is going to be, though.