The boy was put in an induced coma and transferred to Starship from Hawke's Bay Regional Hospital that night.
The school had co-operated fully with the police investigation and the Ministry of Education.
Taradale Primary School's board of trustees chairman Steve Alexander said the school was focusing on supporting the family and the wider school community.
Pupils who might have been upset by the incident had been offered specialist support services.
The Ministry of Education's traumatic incident support team had also been supporting the school and helping it return to its normal daily routines.
Staff had been briefed on how students may respond to the traumatic event, and how staff and pupils could get access to additional psychological support if necessary. The school was said to be coping well with the distressing event.