My brother in law was fired from a law firm for stating (at a casual drinks night) that he believed that, legally speaking, people should not be allowed to chan

My brother in law was fired from a law firm for stating (at a casual drinks night) that he believed that, legally speaking, people should not be allowed to change their gender on their birth certificate. He had worked there for six years as a para-legal, soon to be lawyer. I don't think his cause was helped that the director of said firm had a transgender sister (or brother). He was unaware of this. EDIT: Typo.