[7] In November 2022, Chau filed an application to delay Lai's trial until after the NPCSC decision on blocking the hiring of foreign lawyers such as Tim Owen in national security cases.

[10] As Xinhua reported on 30 December 2022, the NPCSC ruled in favor of the Hong Kong government by granting the chief executive the power to bar foreign lawyers from national security cases.

[11] In November 2022, 6 senior staff members of Apple Daily and Next Digital pleaded guilty to taking part in national security offenses.

"[14] Chau also represents the prosecution for a case against Chan Tze-wah, who has been accused by the government of conspiring to collude with foreign forces.

[16] On 1 July 2020, he was accused of driving his motorcycle into police while flying a flag that stated "Liberate Hong Kong, Revolution of Our Times".

[21] Chau also argued that the 612 Humanitarian Relief Fund, with members such as Cardinal Joseph Zen, should have registered as a society, and that doing so would not infringe on freedom of association.

"[24] In February 2021, Chau told the Court of Final Appeal that the default position the government should hold is that those suspected of breaking the national security law should not be granted bail.

[27] In July 2022, the United States' Congressional-Executive Commission on China recommended that Chau be sanctioned by the US government for his work in prosecuting people under the national security law.