Conflict of Interest due to spousal relationships in an mnc

Hello everyone, This is a throwaway for obvious reasons, my parents are in a huge crisis. My dad was an employee of a company which was taken over by a larger mnc. He has been there for over two decades. Eventually, a couple of years back, he found an opening for my mom who joined the company. At the time, everyone in the hiring process was aware of their spousal relationship. However they were not informed of any portal that requires declaration of coi. They are in different departments and different roles and their work does not overlap. However, this year the legal team brought them under light over breach of coi because of supposed non declaration of their spousal relationship. After multiple meetings over a period of couple of months, the matter was about to be closed when my parents were served with a show cause notice alleging violation of company policy, breach of contract and potential serious threat to their job. There definitely is some dirty office politics which is clear as day however there is no way to prove it. Our arguments are: Nowhere throughout the hiring process was COI ever mentioned and everyone was aware about it The alleged coi portal was not existent at the time of the hiring and once released, was the HR's duty to bring it up and let them know that some action was required on their behalf There has been no communication of any sorts up until the legal meetings and now the show cause notice. What is our way out here? We desperately need the jobs and our life is crumbling. Please please help.