In September 2003, Hasnain and Justice M. A. Matin rejected a contempt of court suit filed by Magistrate Khandker Fatema Begum against United News of Bangladesh, Bhorer Kagoj, and The Daily Star.[2] The news organizations had reported that the magistrate saluted Mirza Abbas, minister for housing and public works, when he entered her court room as an accused in a defamation case.[2]
In January 2009, Hasnain and Justice Mir Hasmat Ali declared illegal rules of the University of Dhaka that prevented madrassah students for admission to seven departments of the university.[10][11]
Hasnain and Justice MR Hasan granted bail to Bangladesh Jamaat-e Islami leaders in a case filed over assaulting police officers during a clash between the party and police in April 2011.[12]
Hasnain was a defense witness for Salauddin Quader Chowdhury appeal against his conviction for war crimes during the Bangladesh Liberation War in 2017.[13] His mother, Zinnat Ara Begum, had written a statement in favor of Chowdhury at his initial trial.[14]