The man accused of killing his tetraplegic friend has taken the stand in the High Court in Christchurch.
Eric Smail, 53, has admitted killing Keith McCormick with a kitchen knife in 2005, but maintains that he is guilty of manslaughter, not murder.
Mr Smail's lawyer, Judith Ablett-Kerr QC, says he did not have the personality structure to deal with the demands of caring for his friend, and the pressures caused him to snap and lose self-control.
Mr Smail told the court he was a sensitive person who reacted poorly to criticism.
He says he met Mr McCormick in a pub in the late 1980s and they became instant friends, partly because of their similar interests in sport and drinking.