An investigation found he did "not act as a reasonable engineer and breached his professional obligations to act competently"
The closure will make 160 people redundant, but not all will be left in limbo.
Stephens was fatally shot by police after smashing up an empty patrol car with a weed slasher.
It comes as more holes in the report into the 2016 death are found.
The woman said she felt sure the man would've attacked had her husband not been there.
The mill will close by June 30, 2021.
Its Swiss owners have agreed to sell the mill to a consortium of investors.
Wai Kōkopu is working to replenish Te Waihī estuary, which is known as one of the most polluted in the country.
Anthony Fane later died in a shootout with police after he led them on a high-speed pursuit.