After making his mind up, Hammett told the Hurricanes board and Roche said the process had been transparent.
"Somewhat disappointingly to many, there is no conspiracy here,'' Roche said. "Mark signalled his thinking to us late last year. There's been ongoing discussions so he leaves with our full support, blessing and we'll do whatever we can to make the next few months as easy on him as we can.''
By season's end, Hammett will have spent four years in the top job at the Hurricanes and his legacy shapes as one where he brought about extensive change in the culture at the franchise.
He cleared out the likes of Andrew Hore and Ma'a Nonu at the end of 2011, while a collection of other senior players also parted ways with the side after Hammett's first season.
Hammett informed his players of his decision to step down this morning and said it was a tough message to deliver.
"The simple reality is tomorrow we are back to work,'' Hammett said. "We've got the Blues next week and that'll be our sole focus from here on in.''
The future likely holds an overseas position for Hammett, something he was never able to experience as a player when a neck injury ended his time on the field in 2004.
"It's always been a dream of mine to perhaps get over there at some stage. In saying that, that's a focus far, far away. At the moment, the main focus still remains our season and the Canes.''
There's been whispers the Cardiff Blues want a Kiwi coach with Super Rugby experience but for next few months, Hammett seems committed to finishing on a high with the Hurricanes.
Skipper Conrad Smith, who was told last Monday of Hammett's decision, said he hoped the side could still succeed this year.
"I'm excited about where we are sitting at the moment in the competition and there's a lot of hard work to do and we've got the right people in place to help us through.''
The Hurricanes will now begin the search for their new coach and hope to have someone confirmed by June.
