It's standard contract law. Every time you purchase anything, you're making a legally binding contract, even buying a sandwich at a shop. Under centuries old contract law, there must be a "meeting of the minds", both parties must understand what they're getting into. If one person makes a obvious mistake (e.g., pricing gas at $0.02/gallon), there is clearly no meeting of the minds, the contract is void, and the seller can ask the buyer for their money back.
I'm completely surprised that 16 people tried to get away with it!
Why would an employee expect different treatment if they believe the laws are just?
Because they don't know the law, and they think they're brilliant and the first person to come up with such a scheme.
For those as confused as I was - Samsung Securities is a small company within Samsung which has a market cap about 1% the size of Samsung's.