The former police minister's lawyer says he gave no operational order.
The NUM says there was a collective bargaining agreement in place at Lonmin in 2012.
The families say the killings at the North West Platinum mine in 2012 cannot be justified.
Amcu has pointed fingers at Cyril Ramaphosa who was a Lonmin shareholder at the time of the shootings.
Advocate George Bizos says the 'no-one-to-blame' conclusion is no longer a proper finding.
The South African Human Rights Commission has strongly criticised the police's conduct.