The assessment is primarily based on the highest-authority and most relevant source provided, a data report from the blockchain analytics firm Arkham. This source is described as explicitly identifying and tracking a wallet entity as the "Mt. Gox Hacker" and providing a direct link to an on-chain explorer to verify transfers. This constitutes direct, primary evidence from a credible, specialized authority. The second source from Arkham, while focusing on the Mt. Gox estate rather than the hacker, reinforces the firm's credibility and its active monitoring of Mt. Gox-related wallets. The remaining sources are of significantly lower authority and relevance; the Wikipedia article offers only general historical context, and the Facebook posts are irrelevant and unreliable. There is no conflicting evidence presented. Therefore, the statement is strongly supported by the best available evidence, which points directly to on-chain data tracked by a reputable firm.