Die varieties, coin errors and die events are three different subjects:
Doubled dies, RPMs, over mintmarks, Over dates (18th, 19th century varieties) are varieties. Mint error coins are a different thing. Die events are just common events that happen to dies. When you mix the terms, you confuse us. If you thought your coin was a doubled die, you would ask: "Is this a DDO
?" If you thought it was a RPM, then ask: "Is this a RPM?" When you ask: "Is this an 'Error'", We are not under standing what you are asking? It is like asking about someone's car: "Is this a car?" The distinction is very vague. Models, years? The more you can add to your question, then we will be able to answer it better.