Whenever Dr. "El Gato" is sweet or just plain nice to his patients, and he's especially great with children and young teens. It was so adorable when he was examining Quinn and told him to follow the light with his eyes, telling him that he sees ice-cream in those eyes, and indeed, Quinn has gorgeous big chocolate eyes.
"Deus Ex Machina" might have been trying too hard with a teenage precocious Littlest Cancer Patient. Some of it feels Narm-esque or trying too hard to be touching, but some parts are well done and genuinely moving to tears of joy. One highlight is "Gato" telling her that she should consider medical miracles as they do happen, and another one is Hooten shaving his head for her. "Gato" mocks him at first, but when he hears why he did it, he just raises his cup for him, impressed and moved.