Wow, while I agree that IB should be punished how can you risk so much without having checked the details...Apparently Cerisano's "Black Swan" nightmare...
I would think that he assumed the date was correct (a reasonable assumption) and I think it wasn't that outsized of a bet for him. So many failures here but this has got to be a black eye for IB. The worlds best technology can't get the dates right on a liquid futures contract.
The title is misleading, according to the trader, the date issue cost him 22.7mil but the judge only awarded him 2.4mil in reparations IB has to pay. There is another thread about it btw
He did check the date. Yes bold is the key bit. That he only got 1/10 of his loss back it a shame especially as it was a winning trade the day earlier.