The Governor's justification could be any of these under Ch. 14.32, Section (2):
(2) The Chief Inspector General shall:
(a) Initiate, supervise, and coordinate investigations, recommend policies, and carry out other activities designed to deter, detect, prevent, and eradicate fraud, waste, abuse, mismanagement, and misconduct in government.
(b) Investigate, upon receipt of a complaint or for cause, any administrative action of any agency, the administration of which is under the direct supervision of the Governor, regardless of the finality of the administrative action.
(d) Examine the records and reports of any agency the administration of which is under the direct supervision of the Governor.
or maybe
(2)(k) Conduct special investigations and management reviews at the request of the Governor.
For the record, "agency" is defined in Ch. 20.03(11), FS as:
(11) “Agency,” as the context requires, means an official, officer, commission, authority, council, committee, department, division, bureau, board, section, or another unit or entity of government.