If you can't hold individuals responsible for signing contracts on the premise that they might not read them, you've simultaneously invalidated most contracts, increased the cost to enter a contract (essentially subsidizing the law industry), and severely limited the ability for individuals to enter into contracts — not to mention infantilizing adults who are fully capable of reading a document before signing it.
Furthermore, this was a severance agreement, not employment agreement, so having a lawyer review your contract is not going to delay you from starting your role.
I have my issues with this situation, but "they might not have read/understood the contract" isn't one of them.