That would not have been possible with human trades
Tell this to Mizuho Securities, where a human sold 620,000 shares at 1 yen instead of 1 share at 620,000 yen. ~$300 million loss in a single botched trade. Humans at both Mizuho and the Tokyo Stock Exchange saw the trade and all declined to intervene because they assumed they had insufficient authority to countermand the trader.
Tell this to Mizuho Securities, where a human sold 620,000 shares at 1 yen instead of 1 share at 620,000 yen. ~$300 million loss in a single botched trade. Humans at both Mizuho and the Tokyo Stock Exchange saw the trade and all declined to intervene because they assumed they had insufficient authority to countermand the trader.