* Safer helmet would not have protected Hughes
* Ambulance delay played no part in death
* Report recommends helmets mandatory for all first class batters (Adds details, quotes, byline)
By Ian Ransom
MELBOURNE, May 11 (Reuters) - 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.