Believers frequently refer to the law and take comfort that "no law was broken". Throughout history, many laws have been enacted, amended or abolished so that justice could prevail and exploitation cease, etc.
In the West, these included the US Constitution's 13th, 15th and 19th Amendments. The Civil Rights Act of 1964 there also prevented discrimination on the basis of race, religion, gender or national origin. In the UK, there was the English Magna Carta of 1215, so long ago!
In the Singapore context as late as 15/09/1961, the Women's Charter was passed to protect the family, maintenance of wives, incapacitated husbands and children and the punishment of offences again women and girls. (https://sso.agc.gov.sg/Act/WC1961)
The fact that it was named "Women's Charter" rather than a more neutral "Matrimonial Laws of Singapore" or similar to it, hints of the "correction" that society then sought to achieve. It was well known that many Chinese men had a few wives/concubines in the past, and not all of them were protected adequately.
The Women's Charter prohibited polygamy. This syncs with God's design of monogamous marriage, between one man and one woman (Genesis 1–2). However, with or without righteous laws of the land existing, believers of the Creator God would do well to do beyond the law of the land (whatever the state of it) and adhere to the standard of the Word of God.