@Prisbrey1, The question stand alone is legitim question. The answer is other. Those errors or varieties are direct proportional with each year production. SM an LD was because two different master dies was use. your year was a clean year from this point of view. To understand more I suggest to try to accumulate the knowledge of minting processes by years. Not each years was same, like not the production lines was. The thinking of "why is not possible or could happened" is just folklore.
Every year production it is very well documented. References are the Congress documents and the Mint Reports. You has your answer.