Up until Fleur had forced him down into an armchair, Roger had been hovering over where Fred had been laying and trying to make him comfortable. Though he was extremely reluctant to just sit down and relax while Fred was seriously injured, he knew he really couldn't do much until this Hestia person got there.
"Is Hestia a Healer?" Roger asked, for the sake of talking rather than any real interest in the answer. Obviously she was or had some kind of medical experience if they were calling her there.
He looked around the living room, trying to distract himself from the sight to Fred for the moment. George was probably going to kill him for getting his brother hurt like this. Because yes, he was blaming himself for messing up with the Floo and their subsequent misadventure.