As the head of investments for New Zealand's $NZ35 billion Accident Compensation Corporation, Nicholas Bagnall is one of the country's highest-paid public servants. According to the ACC's 2016 annual report, which does not disclose the remuneration of individuals, it appears he earned up to $870,000 – almost twice as much as the prime minister.

Helping ensure that New Zealand's only provider of accident insurance coverage has enough money to pay out claims is an important and consuming job. Yet for a few days in early March, Bagnall found himself in the Cayman Islands being cross-examined by an eminent London silk about one of the ACC's least significant holdings.