Brown said he wanted to know why medical professionals sent his son home on two separate occasions.
When Ben first went to the White Cross Medical Centre he was diagnosed with a sore throat, given medication and a pamphlet on meningitis, and sent home.
"Why give a kid a pamphlet on meningitis and say that you might have it but not take it any further?" Brown asked.
The pamphlet stated people should seek medical attention if they were experiencing one or more of the symptoms listed.
By that stage, Ben was experiencing all of the symptoms listed except one and was rushed to hospital by ambulance with suspected meningitis, Brown said.
Five hours later Ben was discharged, still vomiting, diagnosed with the flu.
Brown said the DHB representatives were not able to explain why the hospital doctor sent Ben home.
"I think in those two cases those two doctors had the opportunity to save Ben's life and I think their diagnosis was probably the worst one they could have given Ben. I think somebody's got to be held accountable."
Northland DHB chief executive Karen Roach said an independent investigation would be made to see if anything could have been done differently.
The findings of the external review would be made public, Roach said.
She said meningococcal disease was one of the most difficult to diagnose as patients often had a range of symptoms.
The registrar who attended Ben was a qualified doctor with many years experience in general medicine and emergency medicine, Roach said.
"He had seen and diagnosed meningococcal cases previously. In line with emergency procedures, he had discussed Brown's case with a consultant who also did not consider the case was meningococcal disease on the basis of the clinical evidence available.
"Mr Brown was, therefore, discharged and told to return to the hospital immediately if his symptoms worsened," Roach said.
As a result of the internal review, the DHB had already changed the clinical steps it took to diagnose meningococcal disease and had introduced a new type of blood test (proclacitonin) to help clinicians identify the disease.
Brown said he was disappointed to have heard nothing from the White Cross Medical Centre. "White Cross haven't commented at all. They weren't at the meeting. There's a big blanket of secrecy at the moment," he said.