Protection against what?
Legal action for forging an official document?
It’s real simple, if the head of the Health department had said “I have seen Barack Obama’s vault copy of his Birth certificate, and it proves conclusively he that was born in Hawaii and is a natural born citizen according to the constitution.” That would end the story, instead she parsed her words carefully to say everything but that.
Or in short she knows there is something legally wrong with it she cannot disclose.
You are probably right.