He deduces that someone succeeded in producing the lights using wavelengths, and these caused Andrew to sustain a "hypnagogic trance" that allowed his son to be abducted.
Increased neurophysiological activity in the fusiform face area may produce hallucinations of faces, whether realistic or cartoonesque, as seen in Charles Bonnet syndrome, hypnagogic hallucinations, peduncular hallucinations, or drug-induced hallucinations.