Inspectors made a series of recommendations to the company including better asset integrity management after they noted operator inspections had failed to identify defects they had found, such as corroded ‘fixed’ and ‘spring’ type supports for hydrocarbon equipment.

They also recommended the company improve pressure alerts on its control system.

"[A] drop in pressure did not alert the control room operator to further investigate for potential issues related with a gradual drop in pressure which could be an indicator of a ‘leak event’," the regulator said.

Inspectors also found the company's CCTV system only allowed for operators to view two cameras at a time due to design constraints and software limitations.

"The two CCTV viewed at the time of the incident were not of the offshore production facility, but were of the onshore processing plant," it said.

The regulator said there were key lessons others in the industry that operate unmanned rigs should take on board from the Cliff Head Alpha incident, particulalry with CCTV systems.

"CCTV monitoring systems should ensure sufficient resolution and coverage of the facility to allow onshore operators to adequately detect leaks," it said.

"Onshore CCTV systems should also allow control room operators to view all cameras at all times.

"Alternatively there should be systems in place to ensure operators regularly cycle through all cameras to prevent areas of the facility going unmonitored for long periods of time."

The regualator said control system alarm set points should allow operators to identify potential leaks and processes should be in place to ensure they investigated pressure deviations.

Cliff Head Alpha began operations again on August 9.

A Triangle spokeswoman said the company followed the strict policies and procedures in its oil pollution emergency plan and satisfied safety and environmental requirements.

"No evidence of hydrocarbons was sighted in the marine environment or along the shoreline which reaffirmed Triangle’s finding that the vast majority of produced fluid remained in the platform bund," she said.

"The company responded immediately, liaised with the regulatory authorities and resolved the issue safely and swiftly.

"Scientific monitoring was undertaken to confirm no shoreline sediment and near shore water contamination occurred."

She said a full 25-kilometre stretch of coastline was surveyed.

She said everyone involved in the incident was supportive of Triangle's actions during the incident response and praised it for being open in communication, supportive of resource allocation and overall having a high level of response.

"Further to this Triangle Energy has been proactive with sharing lessons learned with other industry bodies, including Woodside," she said.

"Sharing lessons learned has provided further insight into how other operators manage incidents similar to this."