After Miller arrives at the lab Dr. Carlo refers to him as Colonel while discussing his sudden take over of operational authority of her project with Hammond (who holds the rank of Brigadier General). Military hierarchy would never allow a Colonel to take operational authority away from a higher ranking officer like Hammond.
When Dr. De Carlo is arguing with Miller about the safety of using Butler as a test subject he state it's perfectly safe because the body came from the cryonics lab in Langley and germ warfare research is done on Plum Island in New York. Such research did take place there in the 50's the scope was limited to weapons targeting animal and livestock and ended in 1969 when Presdent Nixon banned biological weapon research.