Henry joined the independent bar in 1999, and since that time has appeared in courts and tribunals in South Australia, Victoria, Queensland, Western Australia, Tasmania and the Northern Territory, Federal courts and tribunals, as well as the High Court of Australia, including in its jurisdiction as a Court of Disputed Returns. Leading cases in the High Court have been in the areas of constitutional law, common law negligence, real property, defamation, civil penalties, and criminal procedure.
Henry has, by ad hoc admission, appeared in litigation in Vanuatu, in cases involving constitutional law, and statutory interpretation, especially in the fields of utilities regulation and equity (constructive trusts).
Prior to joining the bar, Henry completed post graduate study at the University of Cambridge, and was a judicial associate to Justice Legoe in the Supreme Court of South Australia.
He values the cab rank rule, and frequently acts on “both sides” of issues. For example, while acting in litigation on behalf of internet book makers, he also represented Senator Xenophon in the citizenship litigation in the High Court; and for the South Australian Crown concerning allegations by Derek Sands that police defamed him in relation to the murder of Corinna Marr, but also for then convict Henry Keogh in relation to judicial review of the Medical Board about evidence given by forensic pathologists at Keogh’s murder trial. He has acted for pastoral and grazing interests, but also for the Barngarla people in relation to the litigation to stop the nuclear waste dump at Napandee.
In 2002, Henry led in the first successful test case (Al Masri v. Minister for Immigration & Citizenship) challenging indefinite executive detention of an asylum seeker with a writ of habeas corpus.