Last month Corey Sands, 18, was severely injured after doing a back-flip from a high bar into the same pit during an unstructured adults session. He remains in Middlemore Hospital's intensive care unit and has been told he could remain a quadriplegic.
Yesterday his twin Callum told the Herald his brother's breathing had improved, but he was still unable to freely talk after a tracheotomy.
Despite his own injuries, Mitchell managed to walk away from the July 22 lesson. It was only after a trip to a doctor a few days later that the extent of his injury was revealed.
The talented hockey player - who was selected in the NZ under-18 squad before the injury - wore a neck brace for 12 weeks. After experiencing tingling in his arms and legs, there is a possibility he will need an operation to fuse the damaged vertebrae.
WorkSafe New Zealand investigated Mitchell's accident and found no case to prosecute of deliberate non-compliance.
Mitchell's father, Terry Ottow, appealed against that decision, believing his son - who was having his first session at the gym - had not been given adequate instructions and supervision.
Corey Sands was paralysed last month.
In a response to Mr Ottow, WorkSafe said when it was noticed the boys were not jumping correctly, they were stopped. "WorkSafe accepted that the instructions provided by the gymnasium were not as clear as they should have been. However ... our enforcement decisions must be proportionate to the seriousness of the behaviour, and we do not believe that the level of culpability is high enough to warrant prosecution."
Mr Ottow, who said he felt sick after hearing about Corey Sands' accident, told the Herald he was investigating legal options in regards to the two accidents.
But the chief executive of the trust that runs the gym, Oscar Paulich, said he was confident the gym had acted correctly in both cases. The WorkSafe investigation into Mitchell's accident confirmed what he said, and the gym was co-operating with the investigation.
The gym's own investigation into Mitchell's accident found the schoolboys had been told to run through the foam pit. Some students had flipped and dived into the foam, and a staff member put a stop to this as soon as they saw it.
Gymnastics injuries
North Harbour
Gymnastics Centre
Mitchell Ottow, 17
*July 22
*Dived into the foam pit, damaging his C4 and C5 vertebrae on impact during a PE lesson.
*Wore a neck brace for 12 weeks. May need an operation to fuse the two damaged vertebrae.
Corey Sands, 18
*October 21
*Back-flipped from a high bar into foam pit during an unstructured adults' session.
*Could remain a quadriplegic.