Is it actually an error? It's kind of a nice little error. Makes Lucario a lot easier to get.
This thread is a joke imo, it isnt because the set need DP era cards and it certianly isnt POP/PUI fault. I know for a fact, that Mike and all of the people at POP/PUI know exactly what the players want, but are usually handcuffed by what PCL and Japan will let them release. Trust me, they try very hard to get us stuff we want, but a lot of times that is were they are denied what they really want. I would think Mike and the rest of PUI/POP most likely expect reaction like this based on what has happened previously. They do a great job. Just see how much Pokemon has grown since PUI/POP took over and that should be all you need to know.
JMO,
Drew