Phillip Hughes would not have been sufficiently protected from the ball that struck and killed him during a cricket match 18 months ago even if he had been wearing the highest-standard helmet, a report into the Australian's death said on Wednesday.
Hughes was struck on the back of the head by a rising delivery when batting for South Australia in a Sheffield Shield game at the Sydney Cricket Ground in November 2014.
He died two days later in a Sydney hospital at the age of 25.
"The helmet was compliant with an Australian standard, which has since been withdrawn, but was not compliant with the more recent British standard," the report, led by barrister David Curtain, said.
"In any event ... I do not believe the new helmet would have afforded additional protection against the blow given the location of where Phillip was struck, as the protection to the neck, at the rear, is no different."
The report also said the slow arrival of the ambulance that provided medical treatment to the test cricketer played no part in his death.
"Although there was apparently a delay in the ambulance arriving, Phillip was being cared for appropriately in the interim," it added.
"I am of the opinion the attention received by Phillip after being struck had no role whatsoever on his subsequent demise, due to the nature and severity of his injury."
Hughes's death shocked the cricketing world and ignited a debate about safety standards, particularly for batsmen, who can face fast bowling that exceeds 150 kilometres per hour (93 mph).
The report recommended that all first class cricketers should be required to wear the highest British standard (BS 7928:2013) helmets available when batting against fast and medium pace bowling in matches and during practice.
It also recommended wicketkeepers keeping up to the stumps should wear helmets and protective eye-wear.
Players fielding close to the stumps, excluding slips fieldsmen, should also wear helmets, the report said.
The report noted that more international players had adopted the use of stem guards, which are attached across the back of the helmet, as "they see it providing additional safety".
"I would recommend that this device be properly evaluated for functionality and comfort as well as to determine if it materially increases player safety, before making any recommendation as to its use," it said.
Cricket Australia (CA) said it had received the Curtain review last year and would enact new safety measures.
"The global cricket community was deeply saddened by the tragic death of Phillip Hughes and the great loss his family suffered," CA CEO James Sutherland said.
"We have been considering (Curtain's) recommendations and discussing with relevant bodies as to how we best make changes necessary to prevent an accident of this nature happening again.
"While there will always be a small risk we believe that the measures we have already taken and will enact following this review will reduce that risk even further."