Police have been cleared of criminal and procedural wrongdoing in the case.
Newton examined the scene on the day of the shooting and the day after and was present at Taylor's post-mortem examination.
Giving evidence in the coroner's court today Newton said Taylor had been shot three times but the gun had been fired four times.
Taylor was first shot in the front left section of his chest but the bullet did not enter, instead left an abrasion.
Newton said it was his opinion the mobile phone stopped the bullet's lead core from "penetrating Mr Taylor's chest".
He said Taylor had also been shot in the front left abdomen and in the left side of his back.
"In my opinion, Mr Taylor was facing towards the front passenger side door when the first shot through the window was fired.
"The lead core was ... stopped by the mobile phone in his pocket."
Newton said he couldn't estimate how close Taylor was to the vehicle when that shot was fired but it was close enough for glass fragments to land on his clothing. He could not determine the sequence of the remaining two shots which hit Taylor.
Taylor family lawyer Adam Couchman asked how Newton could be sure the bullet that hit the mobile phone was the first fired.
Newton said it was the only one in which the copper casing had separated from the lead core and in experiments conducted, "it was only the very first shot through the intact glass that resulted in the bullet separating".
He also said he could not say whether a sickle and machete a previous witness said Taylor had been "flailing" had come into contact with the police vehicle.
The inquest continues.