The accident in the hyperbaric chamber, and a minor character's subsequent description of a similar accident in another country, are based on the idea that a high-oxygen atmosphere will burn all by itself if ignited by a spark. In reality, the fire danger of a high-oxygen environment is only that flammable materials (paper, cloth, etc.) will burn much more easily and energetically than in a normal atmosphere, and even then only if such materials are directly ignited, not if a spark just occurs somewhere nearby.