While the Liberty looks smaller than normal, that does show the die was over polished, but the missing digit is from a partial grease fill on the die. More than on different happenings can affect a coin. You could have a doubled die, with Machine Doubling, a struck through grease error, a VLDS die strike, with die chips, a die crack and a cud. These all could happen on a coin, and the coin would be undesirable to a variety collector, an error collector might be interested, but probably not everyone would appreciate it. The point I'm making is that more than on happening can happen on any coin. So we should not limit ourselves to one thing happening to a coin.