Do you think it is fair/allowed for an investigator to draw an adverse inference when a Board fails to produce documentation that would put the Board in a good light or when they fail to produce staff to be interviewed?  I know there is no burden of proof

Do you think it is fair/allowed for an investigator to draw an adverse inference when a Board fails to produce documentation that would put the Board in a good light or when they fail to produce staff to be interviewed?  I know there is no burden of proof duty in complaints and the investigator must find the facts. I asked to interview a number of staff and the Board was only able to produce a few staff members.  Granted it is summer etc…