According to Wu, as reported by South Korean media, a South Korean court recently ruled in favor of the South Korean exchange Coinone in a case of Bitcoin double withdrawals caused by a system vulnerability, supporting its claim that users must return all mistakenly withdrawn Bitcoins, deeming this behavior as "unjust enrichment without legal basis." The vulnerability originated in 2018, when Coinone mistakenly restored user account balances without receiving on-chain confirmation, leading to some users successfully withdrawing coins multiple times. Although the court believed the error stemmed from uncontrollable external factors, industry experts pointed out that such vulnerabilities have not been seen in other exchanges, and the court ultimately ordered users to return all double-withdrawn Bitcoins.