By not charting or giving the man medications, the HBDHB failed to provide him with appropriate care and was in breach of the code, according to Hill.
Hill said the man was put at "unnecessary risk" and that the failures by the DHB were the result of "several systemic issues".
The issues included a lack of clarity about which team was responsible for charting patients' regular medications.
HBDHB chief medical officer Robin Whyman said the DHB had employed an extra surgical registrar to help in the Emergency Department during peak patient demand periods since the incident, among other medication safeguards.
A new form has also been introduced in the surgical team to prevent medication errors, while the team highlights this case as part of its staff training, he said.
Hill recommended that the HBDHB develop a formal checklist and action plan, as well as apologise in writing to the man.
Whyman also said the DHB will follow the other recommendations.