For Harry had tried something he never did in healing, something he had always been taught to avoid at all costs. He tried to pass his own magic to the child to try and preserve its life. It was more intimate than simply using spells or runic casting. It used his own life-force to try and save another. It failed, because the damage was too extreme ... but the brief connection he'd had to the little boy was so harrowing, Harry now felt emotionally damaged from the experience.