An estimated 10L of crude was initially spilt from the Hibernia platform's hose-end valve during a connection attempt on December 18, prompting the company to notify authorities.
The sea surface was monitored for five days, with no sheens reported, but heavy seas prevented a remote-operated vehicle being launched to assess the damage.
A sheen was noted on December 27, with a ROV launched three days later confirming the leak.
Offloading to tankers was suspended and production rates at the Hibernia Platform were cut back significantly while Hibernia prepared to mobilise vessels and equipment to stop the leak and begin clean up.
The leak was stopped on January 1, with an estimated 6,000L of crude spilled.
"The Canadian-Newfoundland and Labrador Offshore Petroleum Board will review the methodology used by HMDC to estimate the volume," the Canadian watchdog said.
"The C-NLOPB will fully investigate the incident."
Hibernia's shareholders are ExxonMobil Canada (33.125%), Chevron Canada Resources (26.875%), Suncor (20%), Canada Hibernia Holding Coporation (8.5%), Murphy Oil (6.5%) and Statoil Canada (5%).
