Coroner Richard McElrea made his formal finding public yesterday, noting Mr Hale (22) died from a ''penetrating wound to the right face and head''.
However, Mr McElrea was unable to say what the object was, whose vehicle it came from and where it went after it killed Mr Hale.
In his finding, based on evidence presented at an inquest in Queenstown in September, Mr McElrea described the mystery item as a ''small solid object'' that penetrated the windscreen of Mr Hale's Subaru car as he was driving to his job at a Hawea Flat dairy farmHe found it came from a ''passing vehicle'' and described the item as ''likely to have been a manufactured object and not naturally occurring''.
''It had a semi-circular profile with a diameter of 80 millimetres and was likely coated in soil.''
In his discussion of the evidence presented to him, Mr McElrea said the postmortem found the wound to Mr Hale's head to be most unusual, ''being semi-circular and about 80 millimetres in diameter, similar to a cannonball injury of 200 years ago''.
Pathologist Dr Martin Sage made the cannonball analogy at the inquest, saying ''the temptation to think about metal spheres is quite strong''.
Mr McElrea noted Institute of Environmental Science and Research (ESR) forensic scientists were of the opinion the object was ''likely composed of stainless steel with some dirt or mud on it''.
However, he also noted the Defence Technology Agency (DTA) ''considered it unlikely the object was made of solid steel or similar high density material''.
DTA told the inquest ''if it were metal the density would have been such that it would have penetrated the windscreen at the first impact point''.
ESR had given evidence of ''two main areas of damage'' - one where the object did not penetrate the windscreen and a second where it did.
Mr McElrea noted DTA's comment it was not able to examine the vehicle and windscreen itself.
The agency became involved on August 6, 2014, almost 10 months after the incident.
Mr McElrea said in his release yesterday police returned the car to the family after the ESR examination because it was considered there was ''little to be gained'' from retaining it in police custody.
Detective Sergeant Brian Cameron, who was in charge of the investigation, ''conceded'' at the inquest it would have been preferable if DTA had been able to physically examine the car and windscreen, Mr McElrea said.
''Not unreasonably DTA recommended that physical evidence from unexplained fatal accidents is retained until the investigation process is complete.''
Mr McElrea made no comments or recommendations in relation to Mr Hale's death.
Mr Hale's partner, Danielle Oylear, who was in the car when the object struck, declined to comment on the coroner's finding yesterday.
