That is a stamp, not a signature. It is a facsimile of a signature.
It’s legally binding, but it isn’t a signature. That requires the person to actually sign their name.
Does the expression “rubber stamp” ring any bells?
So you think that the Registrar of Records for the state of Hawaii should be required to personally sign every vital record in order for it to be valid. Interesting.
I would think that since Dr. Onaka is still serving in that position, a notarized statement from him or a deposition taken under oath would suffice.