When Mrs Warren was appointed as the new principal of Iona College in 2014 Mr Warren was the present principal of Eynesbury Senior College in Adelaide.
Te Mata Park Trustee Michael Bate said the tragedy was a very unusual incident.
"It's an extraordinary tragedy and it's very difficult to understand how it occurred," he said.
Bate said he doubted the condition of the track was a factor.
"Thousands of people enjoy the park most days without incident. So it's a tragedy and our thoughts are with [his] family or whanau," he said.
"At this stage it is unclear whether he was on a walking or a biking track.
"The circumstances in which the mountain biker died are not clear yet. Te Mata Park will wait for information about the circumstances of the accident before making any further comment."
Bate said the Te Mata Peak Park extends its deepest sympathies to the family.
"Many people use the park on a regular basis and they too will be thinking of this person and the tragedy. All our thoughts are with the family of the person who died."