"Restructuring happens within any organisation all the time. There were new positions made available and I think those staff chose not to reapply for those positions. There were various reasons for the review - financial, structural.
Mrs Tatham refused to comment on allegations made to the Times-Age of bullying during the period of the review and of a parallel drop in staff morale; the lodging of personal grievance claims with the Employment Relations Agency; and submission to the last board meeting of a letter with 30 signatories alarmed at a worsening work environment at the centre.
She was unaware of any grievance claims or letter to the board, and said any allegations of bullying were "something internal that I'm not at liberty to discuss with you.
"I think, if there are any allegations of bullying, that's serious, and, I think, if there were any serious allegations of bullying they would have been investigated."
The death of Mr Wearing on January 21 was not at all linked to the departure of the half-dozen workers, Mrs Tatham said, but could well have melted away morale from the remaining staff.
"I think when your CEO dies there would be a natural loss of morale for some time and certainly, in that respect, staff morale might be low. The circumstances of Donovan's death were tragic and it would be natural for some to be down."
Mrs Tatham would not be drawn on the vacant chief executive role or when the vacancy would be advertised.
Other routine Government reviews looming for Taratahi included a Targeted Review of Qualifications and an External Evaluation and Review, she said.
Today, there were 45 staff members and close to 100 trainees at the Wairarapa campus, she said, and UK exchange students from Walford and North Shropshire College will complete an almost three-week study programme at the centre from Monday.
A memorial service was to be held for Mr Wearing today at the campus near Masterton.