The incident occurred at the end of the 28th over, when there was an altercation between du Plessis and some of the New Zealand players following AB de Villiers' crucial run-out. Mills, who was not in the playing XI for New Zealand, ran onto the field with drinks during the short break after the wicket and together with Vettori and several other New Zealand players became embroiled in a heated exchange with du Plessis and de Villiers, who had remained on the field to offer support to his team-mate. The exchange ended with du Plessis shoving Mills and umpire Rod Tucker stepping in between the players.
The disciplinary charges were laid by on-field umpires Tucker and Aleem Dar, third umpire Kumar Dharmasena and fourth umpire Nigel Llong. They were then considered by match referee Roshan Mahanama, who imposed the sanctions.
Mills was fined 60% of his match fee for breaching Article 2.2.4 of the ICC Code of Conduct, which is a Level 2 offence relating to "inappropriate and deliberate physical contact between players". He was also fined a further 60% of his fee for breaching Article 2.2.11 of the code, a Level 2 offence which relates to conduct that is "contrary to the spirit of the game" or "brings the game into disrepute". That means Mills, who has been ruled out of New Zealand's semi-final clash by injury and replaced in their squad, will have to pay 120% of his original match fee as punishment.
Vettori was fined 50% of his match fee, also for breaching Article 2.2.4 of the Code, and a further 40% of his match fee for breaching Article 2.1.8 which is a Level 1 offence that relates to conduct "contrary to the spirit of the game" or "brings the game into disrepute". Du Plessis, meanwhile, has been fined 50% of his match fee for breaching Article 2.2.4 of the code, a Level 2 offence.
"It was a very important time of a crucial match for both sides but there is never any excuse for deliberate physical contact in international cricket," said Mahanama. "Vettori and Mills continued to act inappropriately and contrary to the spirit of the game throughout, hence the second charges were laid against them. In determining the punishment I have taken into consideration the fact that none of these players has previously been involved in similar breaches of the code."
Mills pleaded not guilty to the charges and his case was thus considered in a full hearing by Mahanama in the presence of the four umpires, Mills and the New Zealand team manager. He was found guilty after Mahanama heard oral submissions from Mills and the match officials and considered video evidence of the incident. Mills has a right to appeal both findings and has 24 hours from receipt of the decision to lodge a notice of appeal. The other two players pleaded guilty to the offences and accepted the proposed sanction so there was no need for a formal hearing in respect to those charges.