Retired pathologist Jan Botha said there would be a lapse of a few seconds for a person being told there was an intruder in the house and the police must be called.
She would have been behind a locked door and would probably have been in a panic.
He said if the shots were fired in four to five seconds and she was struck, she may not have been able to respond.
The court was dealing with whether Steenkamp could have cried out from behind the toilet door before Pistorius shot her dead.
Steenkamp was shot in the hip, arm and head at Pistorius’s home on Valentine’s Day last year.
Pistorius has been charged with the murder of Steenkamp and contraventions of the Firearms Control Act.
He said he thought there was an intruder in his house when he shot and killed Steenkamp in the early hours of Valentine’s Day morning in his toilet last year. She had been spending the night.
He allegedly fired a shot from a Glock pistol under a table at a Johannesburg restaurant in January 2013.
On September 30, 2012 he allegedly shot through the open sunroof of a car with his 9mm pistol while driving with friends in Modderfontein.
He has pleaded not guilty to all charges.
– Sapa
Download our app and read this and other great stories on the move. Available for Android and iOS.