A Transport Accident Investigation Commission report said there were no witnesses to the crash, but about six minutes before the estimated time of the crash, Mr Saxton flew past a barge being skippered by a friend.
"Telephone company records showed that in the next few minutes, the pilot had received and sent cellphone text messages, including one sent close to the estimated time of the accident to the barge skipper," the commission report says.
During a eulogy at Mr Saxton's funeral in November 2008, Minaret Station owner Jonathon Wallis said he had been on a barge crossing Lake Wanaka when Mr Saxton flew up from behind in his helicopter and passed over the barge to surprise him.
He remembered Mr Saxton's "cheeky" smile from within the helicopter as he flew off towards Wanaka.
Mr Wallis could not be contacted yesterday.
Mr Saxton, who was on bail at the time of the accident pending an appeal against a conviction alongside his father, Dave Saxton, for greenstone theft, disappeared while on a routine flight to Wanaka on November 1, 2008.
His body and the wreckage of his Robinson R22 helicopter were retrieved from the bed of Lake Wanaka about four days later.
The wreckage showed a "mast bump" occurred before the helicopter hit the water, the commission said. A mast bump occurs when a two-bladed helicopter's main rotor hub [head] makes contact with the main rotor mast.
"The head literally 'bumps' the mast and can damage or snap it off," the MyAviationSchool.com website says.
The mast bump probably followed a low-G condition caused by turbulence or some other undetermined event, the report said.
"Anecdotes suggested the pilot had a preference for flying fast, which would have exacerbated the reaction of the helicopter to a low-G condition. If the pilot had been preoccupied with his cellphone, he would have had less time to take the appropriate recovery action."
Close friends of Mr Saxton had observed him flying while texting on a cellphone without taking his hands off the flight controls, the report said.
Mr Saxton was observed flying his helicopter in the direction of ranges east of Lake Wanaka which could have caused turbulence, such as "short, sharp bumps in the lee of the hill that ... was approaching,"Wreckage distribution on the lake floor suggested Mr Saxton's helicopter was largely intact when it entered the water at high speed in a near-vertical, nose-down attitude.
"A main rotor blade had struck the cabin and almost certainly caused the pilot's fatal injury," the report said.
The TAIC has previously reported on accidents where cellphone use by a pilot or vessel skipper might have been a contributing factor and made safety recommendations to the relevant regulatory authorities.
No new safety recommendation has been made by the TAIC in its report on Mr Morgan's crash.
