The Wellington coroner has heard that Hutt Hospital has updated its procedures since the death of a woman there.
The woman died after a breathing tube dislodged, leading to a cardiac arrest and respiratory failure.
Ian Smith has reserved his decision on the death of Jacqueline Senibuli, who died from complications of Guillain-Barre syndrome in July 2008.
A tube had been inserted to help her breath and the doctor treating her, Kevin O'Connor, had only just arrived home when he was called back to the hospital because she had gone into cardiac arrest.
During today's hearing the dead woman's son asked hospital staff why no doctor was available on site to deal with the emergency.
The court heard the specialist on duty was already involved in emergency surgery and the incident involving Mrs Senibuli was very rare.
Earlier, the coroner was told that the delay caused when Mr O'Connor was stopped by a police officer as he sped back to Hutt Hospital on the emergency call did not contribute to Mrs Senibuli's death.
Mr O'Connor was stopped for speeding and was breath tested before being allowed to continue.
The Coroner has questioned why the officer did not exercise discretion and let him drive on when he had established he was a doctor.