A true non-smart parallel is this. You and I agree on a sporting event between humans. Because I want to construct a fantasy, let's just say it's a three-point basketball contest between adolescents (under 13).
The observer will pay $100 dollars per blocked shot, and earn $1 per 3 point play made. All the games are played 1v1. To the untrained basketball player participants, this may seem to be a fair game. After all, it's quite rare in a real basketball game to see a 3 point shot blocked. So they sign the contract, fully agreeing to pay $100 per blocked shot and earn $1 per made 3 pointer.
To game this as a participant, I go to the ends of the earth ( I hear Sudan and the Netherlands are both nice this time of year ), and find a 6'8 ,215 lb boy and recruit him to play for me. He proceeds to block every single shot in every contest, winning hundreds of thousands of dollars and bankrupting the organizers. Just to further weight this, I also hire an opposing player who is only 4'3 to shoot as many 3 points as possible as quickly as possible.
Now, they signed the contract and agreed to it. They didn't have a clause for height, or any sort of caps, and now they have unlimited downside. How would the legal system handle this? Do you think they would release the participants liability? Perhaps, but not likely if they didn't sign the contract under duress. They fully agreed and had consideration ( the $1 per 3 point made ).
It's a contrived example, but it's useful to show that technicalities can be exploited in real world contracts just the same as smart contracts.