Nikon’s Small World in Motion contest disqualified its winning entry. The video by Ning Xu used generative AI for postprocessing. Experts noted it contained structures that do not exist in biology. It also carried an AI-identifying SynthID watermark. Nikon adjusted the rankings and named a new winner. The decision was based on eligibility rules, not the entrant’s intent. Nikon will revisit rules and evaluation procedures for future entries.