While it was rare during his playing days for an opponent to better him in the heat of the front row, after his playing days the former giant prop has been lowered by dementia diagnosis and the degenerative brain condition CTE (chronic traumatic encephalopathy).
In December 2020, Hayman and 1970s and early 1980s All Black Geoff Old told the Herald they had been in contact with British-based lawyers about their post-playing medical conditions.
Hayman initially declined offers to be tested to ascertain any damage to his brain over the course of his playing career. However, he relented after thinking of how his story could help fellow and future players.
He is now among more than 100 former rugby players who are taking legal action against World Rugby and the England and Wales rugby unions amid claims those sporting bodies failed to protect them from permanent injury relating to repeated concussions.
In October, Hayman was convicted of drink-driving after being caught behind the wheel while more than four times over the legal alcohol limit.
He said he was not “in a good place” when he was pulled over by police while driving in Ōpunake, in south Taranaki.
As well as suffering early onset dementia and depression, he said he was grieving the recent loss of his mother.