A number of managers and clinicians wrote to the CDHB chief executive with allegations against him in November 2019, according to the Employment Relations Authority (ERA).
The CDHB commissioned an independent investigation and Humphrey sought special leave for two weeks in March last year.
When he requested to return to work in April, it was refused.
New Zealand was under a national lockdown because of Covid-19 from late March to mid-May last year and Humphrey was not allowed to return to the CDHB.
"The role of MOH is extremely important during a global pandemic," the ERA says.
It was not until October 14 that the CDHB's acting chief executive Dr Peter Bramley wrote to Humphrey confirming the decision to dismiss him.
Humphrey has now lodged a statement of problems to the ERA, asking to be reinstated.
In his letter, Bramley said he had concluded Humphrey's employment relationship with the CDHB was "irremediably untenable", resulting in an "irretrievable breakdown".
"Dr Bramley also had concluded that Dr Humphrey's actions in respect of Dr Ramon Pink and Environment Canterbury had brought CDHB into disrepute, amounting to misconduct," the ERA says.
It is unclear exactly what Dr Humphrey's alleged actions were.
His argument is that the CDHB did not make a genuine attempt to address relationship difficulties with colleagues arising from the conflicting loyalties and tensions.
He said there is little prospect of him obtaining employment in Canterbury or elsewhere in New Zealand, with his designation as an MOH likely to be removed as a consequence of his dismissal.
The Employment Court will now hear his case at a later date.
Humphrey's said he is pleased the ERA has accepted his argument that the case should be dealt with by the court.
"There are a number of complicated issues to address and I believe the Employment Court is the best place to deal with these.
"It has been said that there has been an irretrievable breakdown in my relationship with my employer, CDHB, and I am contesting that."
