Bithumb is making an all-out effort to recover every last bitcoin that was paid out in error. It is also reportedly reviewing legal action behind the scenes in case some customers refuse to return the funds. Virtual assets are not legal tender under the law. In the legal community, the prevailing view is that "a civil obligation to return is likely to be recognized, but whether criminal punishment applies is a separate matter."
A Bithumb official said in a call with ChosunBiz on Jan. 9, "We are contacting, one-on-one, customers who received bitcoin and disposed of it immediately to persuade them to return it and to coordinate how that will be done."
On the afternoon of the 6th, Bithumb caused a system incident during the payout process for a "random box" event by mistakenly entering the unit as "bitcoin (BTC)" instead of "won." It had planned to pay the equivalent of 2,000 won per person, but 2,000 BTC was paid to some users, resulting in a total of 620,000 BTC being mispaid to 249 people.
Given that the price of bitcoin at the time of the incident was in the 98 million won range per coin, the total comes to about 60.76 trillion won. Although Bithumb halted transactions in about 40 minutes, 125 BTC (about 12.3 billion won) has not yet been recovered. Among this, dozens sold the bitcoin and withdrew about 3 billion won in cash, and about 10 billion won was reportedly used to repurchase altcoins.
◇ Civil: "A typical 'erroneous remittance'… the principle is return"
The legal community views this case as a typical "erroneous remittance." An erroneous remittance refers to a case in which the sender transfers an asset by mistakenly specifying the recipient, amount, or quantity contrary to intent. Civilly, the key issue is whether it constitutes "unjust enrichment."
Attorney Choi Young-no of Law Firm Barun said, "Holding a virtual asset that was paid by mistake constitutes a benefit without cause and gives rise to an obligation to return it," adding, "Virtual assets, like cash, are subject to a claim for the return of unjust enrichment."
If Bithumb prevails in a lawsuit for the return of unjust enrichment, the customer may have to disgorge the proceeds from selling the bitcoin and could also be liable for the company's attorney fees.
If the bitcoin has already been sold, returning it in kind is impossible, so a monetary return obligation may arise based on the value at the time of sale (the price converted into money). If return is delayed, default interest may accrue, and there is talk that Bithumb could seek preservation measures such as provisional seizure along with a civil suit.
However, some note that separate proof would be required for third-party losses resulting from low-price sales. Around 7:30 p.m. on the 6th, when Bithumb mispaid bitcoin, a large volume of sell orders poured onto the exchange. As a result, the price of bitcoin plunged to 81.11 million won, 17% lower than on other exchanges (about 98 million won), and a panic sell continued for about 10 minutes.
Accordingly, Bithumb will pay 20,000 won to customers who were accessing the Bithumb app and web at the time of the incident. Customers who sold at low prices during the incident window (7:30–7:45 p.m. on the 6th) will receive the full (100%) difference from their sales and an additional 10% as compensation.
Choi said, "Because Bithumb has said as a matter of policy that it will compensate for the losses, this may not become a major issue," but added, "If it is evaluated that, due to the erroneous remittance, the recipients could have been expected to dump all at once, causing only the exchange's market price to crash, there is room for liability for damages to be recognized."
◇ Criminal liability hinges on 'awareness'… punishment is a separate question
In criminal liability, "intent" and "disposal after awareness" are considered key, and many say careful interpretation is needed.
Choi said, "If a person disposed of it without knowing it was sent by mistake, it is difficult to establish criminal liability."
However, because this event had previously notified that the prize ranged from 2,000 won to up to 50,000 won, there is also criticism that if someone recognized that thousands of bitcoins had been paid and still disposed of them, it could be problematic.
Even so, the prevailing view in the legal community is that there are limits to applying embezzlement or breach of trust under current precedents.
Choi said, "The Supreme Court has not regarded virtual assets as 'things' under the Criminal Act and has denied the establishment of embezzlement, and its position is that even if there is an obligation to return due to an erroneous remittance, failure to perform it does not constitute breach of trust," adding, "In the end, even if users refused to return or disposed of the assets, they would bear civil liability to return them, but the likelihood of criminal punishment is not large."
◇ Possibility of a probe by authorities… a burden across the exchange industry
There is also the possibility that financial authorities will look into Bithumb's incident response and whether there was a failure of internal controls. Under the Act on the Protection of Virtual Asset Users, which took effect in Jul. last year, when a system incident occurs, a virtual asset service provider bears obligations to protect user assets and to prevent and respond to incidents. If authorities determine this was violated, sanctions or recommendations for improvement may follow, which could lead to strengthened internal control standards across the exchange industry.
Ultimately, the dispute over the unrecovered 125 BTC at Bithumb is likely to escalate into civil litigation. The legal community assesses that "while refusal to return is unlikely to be legally tolerated, there are considerable hurdles to imposing criminal liability."