The starting point for the new research in Anatomical Record was the realization that the brain of the Flores skull (at 400 cc, the size of a grapefruit and less than one-third of the normal size for a modern human) is simply too small to fit anything previously known about human brain evolution. In addition, the stone tools found at the same site include types of tools that have only been reported for our own species, Homo sapiens.
Brain size of the Flores hominid, originally called Homo floresiensis, is known only from the main specimen discovered there, the LB1 skeleton. Skeletal fragments have been attributed to eight other individuals, but nothing can be said about their brain sizes. (They are small-bodied, but that has never been at issue.)
The new exhaustive research shows that the LB1 brain is simply too small to have been derived from H. erectus by evolutionary dwarfing, as was claimed by those who discovered it. In fact, the size of the brain corresponds very closely to the average value for modern human microcephalics.
No doubt Hawks will be looking into this paper soon.