In 1940, during the Soviet occupation of Bukovina, Hacman fled into unoccupied Romania with his papers, which eventually ended up at the Iași chapter of the National Archives. Initially staying with his wife's parents in Focșani, he then moved to Bucharest, where he was a member of the inter-university council. As a member of the Senate for the sole ruling party, the Party of the Nation, and representative for Bukovina, he advocated for a declaration expressing the country's willingness to fight and regain the occupied territories. He addressed a petition to King Carol II expressing the inhabitants' outrage over the occupation. Meanwhile, he took part in the final operations of the Cernăuți law faculty, which had taken refuge at Bucharest. In autumn, he obtained approval from Education Minister Traian Brăileanu, himself a Bukovina refugee, for himself and his former colleagues to transfer to the law faculty of the University of Bucharest.