A neurosurgeon has told a court that significant force caused the injuries to a Radio New Zealand journalist attacked in Wellington.
Nicho Waipuka, 20, and Manuel Robinson, 18, are charged with the murder of Phillip Cottrell in a central Wellington street in December 2011. They deny the charge.
Mr Cottrell was on his way home just after 5.30am after finishing an overnight shift when he was attacked on 10 December.
The 43-year-old suffered severe head injuries and died in hospital the following day after being taken off life support.
Martin Hunn operated on Mr Cottrell and told the jury in the Wellington High Court on Friday that he had extensive fracturing in his skull and extensive bleeding, which gave him an extremely small chance of survival.
Mr Hunn said a significant amount of force caused the injuries. He said it was highly unlikely that contact with the edge of a piece of concrete paving where Phillip Cottrell was found could have accounted for the multiple fractures to his skull.
On being shown two pairs of sports shoes by the Crown, which are exhibits in the trial, Mr Hunn said it was possible that parts of the shoes could have caused the injuries if used with sufficient force.