The British-flagged Bayesian, a 56-metre-long superyacht with 22 people aboard - 12 passengers and 10 crew - capsized and sank on Monday within minutes of being hit by a pre-dawn storm while anchored off the coast of northern Sicily.
Seven people are believed to have died in the disaster while 15 survived, including Lynch's wife, Angela Bacares, who is the owner of the Bayesian. Five bodies were found inside the wreck. Emergency services are still trying to locate the body of the last missing person, Lynch's daughter Hannah, 18.
"The boat suffered a series of indescribable, unreasonable errors, the impossible happened on that boat ... but it went down because it took on water. From where, the investigators will tell," Giovanni Costantino told Reuters.
It was also reported he was spoken to for about two hours by Italian investigators.
Earlier this week media, including the BBC and ABC, reported the yacht's captain was James Cutfield from New Zealand. He had told local media of the waterspout that engulfed the vessel, saying they "just didn't see it coming."
The vessel has been refitted twice, last in 2020, but not by Perini.
The chief executive ruled out any design or construction errors, which he called unlikely after 16 years of trouble-free navigation, including in more severe weather than on Monday.
He blamed the Bayesian's crew for the "incredible mistake" of not being prepared for the storm, which had been announced in shipping forecasts.
"This is the mistake that cries out for vengeance," he said.
Costantino said passengers should have been summoned out of their cabins and assembled at a point of safety while the boat was being prepared for the storm by pulling up the anchor, closing doors and hatches, lowering the keel to increase stability and other measures.
"Had correct procedures been followed, all passengers would have gone back to sleep after one hour "and the next morning they would have happily resumed their wonderful cruise."
Another yacht anchored near the Bayesian escaped unharmed.
The captain of the sunken yacht and other crew members have not commented publicly on the disaster, while Italian prosecutors investigating it were due to hold a news conference on Saturday.
Italian officials confirmed they had retrieved on Wednesday the bodies of Jonathan Bloomer, a non-executive chair of Morgan Stanley International, and Christopher Morvillo of the law firm Clifford Chance, alongside their wives, Judy Bloomer and Neda Morvillo.
The body of the onboard chef, Canadian-Antiguan national Recaldo Thomas, was recovered near the wreck on Monday.
Mariani said it was possible that Hannah Lynch's body was not in the boat, but might have been swept out to sea.
Fire brigade spokesperson Luca Cari said if her body was still in the yacht it could take time to find, given the difficulty divers were having in accessing all areas of the boat, which is lying on its side at a depth of 50 metres.
Challenging conditions
A judicial investigation has been opened into the disaster, which has baffled naval marine experts, who say a boat like the Bayesian should have withstood the storm.
Specialist rescuers have been searching inside the hull of the sunken yacht for the past three days in what they said were extremely challenging conditions due to the depth and the narrowness of the places that the divers are scouring.
The fire brigade compared the efforts to those that were carried out, on a larger scale, for the Costa Concordia, a luxury cruise liner that capsized off the Italian island of Giglio in January 2012, killing 32 people.
Once the final body is recovered, experts will have to decide whether, or how, to salvage the vessel.
Costantino said the yacht's automatic tracking system suggested that it took 16 minutes from the moment the storm first hit to the sinking.
He said it was clear the ship took in large amounts of water, adding that investigators would need to see what doorways or hatches might have been left open, focusing notably on a main door located on the left side of the yacht.
"A Perini boat survived the Category 5 Katrina hurricane. Do you think one couldn't survive a waterspout here," he told Corriere della Sera newspaper, referring to a type of tornado which is believed to have hit the Bayesian.
Under maritime law, a captain has full responsibility for the ship and the crew, as well as the safety of all those aboard.
The captain of the Costa Concordia, Francesco Schettino, is serving a 16-year prison term for his role in the 2012 disaster after he admitted to sailing too close to underwater rocks.
- additional reporting by RNZ
