Yes, I think Froch would have won on a split decision if it had gone the distance ( two judges having Groves just ahead at the end ). However, I'd say more likely Froch would have still won inside the distance, but in a more satisfactory manner.
Although Groves will initially be disappointed ( well, mad ! ) it could potentially work out well for him.
He surprised many folk by just how good he was last night and won over more supporters. Extraordinary how he turned these boos to cheers inside the arena. And that controversial end has left him with much more sympathy and more likely to get a return match than if he had been conventially taken out by Froch after a gallant fight.