Shortly afterward she noticed three bruises around the baby's chin, lip and neck area and he projectile vomited three times. When she picked him up from daycare later that day staff suggested she take him to a doctor as he was showing signs of pain.
She took him to Tokoroa Hospital and he was transferred to Waikato Hospital for tests, which showed a a small subdural haemorrhage and retinal haemorrhage in both eyes.
Doctors said the injuries were non-accidental and were either from shaking or shaking impact. Bruises on the baby's face and neck were also consistent with having been grabbed by fingers and a thumb.
The baby appeared to be thriving however a paediatrician's report said 70 per cent of shaken babies will have long term co-ordination problems, Judge Weir said.
Defence lawyer Herman Roose said Carlson was remorseful and had a "real sense of shame".
He said Carlson's family, some of whom were in court to support him, had told him Carlson had "owned the incident from the outset".
Crown prosecutor Amanda Gordon said offending of this type had to be treated sternly.
Despite efforts to educate the public, many people still did not understand the consequences of shaking a baby, she said.
Judge Weir said Carlson had told a probation officer he had handled the baby roughly but said he had never meant to hurt him. He had since self-referred to a number of courses including anger management, the judge said.
"Offending against little children has to be regarded seriously by the courts," the judge concluded.