This matter has been decided without an oral hearing.
 At issue in this application for leave to appeal is whether the Labour Appeal Court created new rules on proof of common purpose and, if it did, whether – in the context of the requirement that dismissals be substantively fair – these rules accord with this requirement. The issue arises in the context of the dismissal of employees for the serious assault of a manager employed by the respondent, Marley Pipe Systems SA (Pty) Ltd. The assault took place during the course of an unprotected strike at the respondent’s premises on 14 July 2017. The applicant, the National Union of Metalworkers of South Africa (NUMSA), a registered trade union, comes before us acting on behalf of only 41 of a much larger number of dismissed employees.
 In July 2017 a wage increase agreement affecting the plastics industry was reached pursuant to sectoral level bargaining under the auspices of the Plastics Negotiating Forum. The respondent’s business is within the plastics industry. On 13 July 2017 the respondent communicated the increase to NUMSA shop stewards. On that same day the shop stewards, in turn, communicated the increase to the respondent’s employees who are NUMSA members. Unhappy with the increase, NUMSA members who worked on the morning shift embarked on an unprotected strike on the morning of 14 July 2017. They first gathered at the canteen waiting to be addressed by Mr Ferdinand Christiaan Steffens, the respondent’s head of human resources. When he did not arrive, they moved towards the respondent’s administrative offices carrying placards which called for the removal of Mr Steffens. This was still in the morning.
 Mr Steffens came out. The striking employees surrounded and assaulted him severely. He was punched and kicked whilst he lay on the ground. Rocks were thrown at him. He sustained injuries all over his body. He was also pushed through a glass window. He managed to leave the premises and went to seek medical help only after two employees who were not part of the group on strike came to his rescue. On the same day the respondent called the police to quell the unrest. It also secured an order in the Labour Court interdicting the employees from committing acts of violence, intimidation and harassment and engaging in the unprotected strike.