Arnause is a legal practitioner and dispute resolution specialist with deep expertise in labour law and workplace relations. He has chaired disciplinary and grievance hearings, initiate disciplinary processes, and conduct investigations into employee misconduct and broader organisational matters. He also preside over arbitrations, including private arbitrations, and chair appeal hearings such as MEC Appeals Committees. 

Arnause mediates disputes ranging from wage negotiations to executive conflicts, political party disputes, and community or religious disagreements. He litigates in both the Labour Court and the High Court. 

Over the years, he have helped resolve high profile matters in mining, aviation, petroleum, glass, higher education, and coal. He assisted in resolving a commercial dispute between the Departments within Government and the private sector, played a role in addressing a six?month mining strike in 2014, and facilitated numerous section 189A retrenchment processes in the mining industry.