A witness who heard the gunshots that killed Reeva Steenkamp told the High Court in Pretoria on Monday there could not have been shots fired while she was asleep.
Barry Roux, for murder-accused paralympian Oscar Pistorius, asked Michelle Burger if there could have been more shots fired while she was sleeping.
"No it's not possible. I woke up from the screams of a woman. I made a phone call [to security guards], then I heard the petrified screams of a woman and the shots," she said.
Roux and Burger seemed at times to get frustrated as each felt the other was not understanding them.
"What was my question? Because I think there is some misunderstanding," Roux asked her.
Pistorius is accused of the premeditated murder of Steenkamp, of illegal possession of a firearm and ammunition, and recklessly discharging a firearm in public.
His lawyers will argue that he mistook her for an intruder when he shot her through the toilet door of his home in the Silverwoods Country Estate around 3am on February 14 last year.