Included in the "gap" in documents were a comprehensive and detailed impact assessment, emergency oil spill response plan and appendices referred in documents considered by the EPA during the process.
Without considering these documents and reports, the EPA was unable to fulfil its role, and erred in the law, Mr Hikaka said.
It also meant the public did not have a complete understanding of the issue during the consultation process, he said.
Mr Hikaka also told the court Maritime New Zealand, in its role to uphold marine protection laws, had received the full package of documents.
"The EPA and therefore the public through the consent process needs the same information [as Maritime New Zealand] on what the impact on the environment and existing interests will be," he said.
The case, which is before Justice Alan MacKenzie, continues.