Perhaps a  new numismatic collecting category is required? Blunder collecting...

As it can be explained, a few intact specimens slipped by the manufacturer who eagerly holed-out the "49" as to remove the obvious timing blunder as Alaska became the  49th state. This is not an error. It's an unfortunate timing of the Alaska statehood event when this SCD was struck.

Actually, SCD HK-722A can be claimed as a specimen from the Territory of Hawaii period (and while the US had only 48 states).

Why does the NGC census reflect a population of 4 for So Called Dollar (SCD) HK-722A?

NGC does not grade holed specimens, but rather pushes them into the NGC DETAILS realm. Hence the low population of intact HK-722A in the NGC census.

I enjoy seeing newbie collector faces when I tell them this specimen is from the alternate reality of the United States of which Hawaii was the 49th state and Alaska was never a state...