Canon Trufax
Ross was obviously just resting unconscious, having not been hit directly but rather impacted by the surrounding disturbance created by the weapon's discharge. I know the airstrike on the factory looked bad, and all, but Torchwood and co. have already demonstrated that bombing buildings is no obstacle to walking away from them. While Martha was changing into her street clothes, the Doctor went round to bring him tea. To cheer him up, the Doctor chatted about an old UNIT hand named Benton, so very like young Ross himself, and how the Doctor had always intensely admired and been attracted to him.