Pretoria - A defence expert at the Oscar Pistorius trial has been under fire throughout Thursday's proceedings.
Sports scientist Professor Wayne Derman earlier spent hours describing to the High Court how the athlete's behaviour on the night he killed Reeva Steenkamp was a natural, but terrified fight or flight response.
He also testified that Pistorius has an increased response to dangerous or stressful situations because of his disability, his life experience and training as an athlete.
Pistorius claims he shot Steenkamp thinking she was an intruder after hearing a series of noises coming from his bathroom.
Prosecutor Gerrie Nel began his cross-examination by quizzing Derman about his report, asking “as what” he was giving evidence.
Derman said he was an expert witness who was describing his experiences treating Pistorius and not providing any forensic evidence.
Nel said that Derman's report did focus on accountability, and that his testimony appeared to be that of a character witness rather than an expert witness.
Derman defended his expert status by mentioning his degrees, years of experience in the field of neurophysiology and working with disabled athletes.
Nel said that by basing his report on experiences with Pistorius, Derman was providing character testimony. He added that an expert witness requires a large amount of objectivity, which Derman does not have because it would harm his patient.
Derman said he would never come to court with a biased report, as the truth came before his client's welfare.
Nel attempted to introduce rules which govern psychologists in court cases, but defence advocate Kenny Oldwadge objected to this, saying it was not relevant. Judge Thokozile Masipa agreed with Oldwadge and sustained his objection.
Nel then asked if Pistorius was more than a normal patient to Derman. The doctor responded that he was closer to other disabled athlete's he worked with, largely because Pistorius won so many medals, necessitating Derman spending time with him during doping tests.
Nel asked if Derman had an intimate relationship with Pistorius. Derman replied that often when working with athletes, especially the disabled, a bond often forms between doctor and patient.
He added that he made sure to have his own legal representatives to ensure he didn't provide biased testimony or break patient/doctor confidentiality.
Nel queried Pistorius' discussions with Derman about the night Steenkamp died.
Derman said he spoke with Pistorius before the bail application and again prior to the psychological evaluation last month, and he said he'd read the court record as well.
These meetings and the record were how Derman constructed the version of events in his reports of the shooting. However, he admitted he had not taken notes when discussing the incident with Pistorius.
Nel attacked Derman's status as an expert again, saying he was unsure on key aspects of his testimony and didn't have important notes.
Derman also admitted he had not received a formal, written request to testify.
The doctor said he was not in court to testify on why Pistorius shot Steenkamp, but rather for his work on anxiety among the disabled and the fight or flight response.
Nel asked why it was important for Derman to hear Pistorius' version of events about the shooting. Derman said it was necessary for him to hear firsthand to ensure he felt comfortable to testify in the trial.
When asked why he didn't feel it was important to write down notes about his interview with Pistorius, Derman said he only wanted to hear certain details, like if Pistorius was on his stumps at the time of the shooting.
Earlier, Derman testified that during a fight or flight response in a tense situation, the “thinking”, conscious brain is less active.
Nel asked if Pistorius' version that he thought an intruder was in his home was thrown out by the court, would Derman's evidence still hold? Derman said all of his studies and other written evidence would still hold true, but his personal analysis of Pistorius' version would be incorrect.
He stood by his evidence that people with disabilities still feel more threatened than able-bodied people.
Derman said that Pistorius often downplayed his disability, but that he was still affected by it.
Nel asked what the first startle response was for Pistorius on the night of the shooting. Derman said that it was most likely the sound of the bathroom window opening, and Pistorius’s first response was to freeze.
Nel asked if after Pistorius froze, did he enter “fight mode”? The athlete’s version is that he then retrieved his firearm. Nel said Pistorius wasn't in fight mode when he armed himself. He had to think about where the gun was, as he was sleeping on the other side of the bed.
“That all implies cognitive function... in order to fulfil the fight or flight response,” said Derman.
He said the first sound kicked off the fight or flight response. “Whether this is enough to cause the whole incident, I don't know,” he added.
When asked again whether the single startle response would have accounted for the whole incident, Derman said he could not hypothesise over such a scenario.
Nel said that as an expert, this was his job, and to not be so concerned only with the concrete facts of the case.
The prosecutor returned to the sequence of events after Pistorius had armed himself.
According to Derman, Pistorius “ran” down the passage towards the bathroom, but Nel said that word was never part of the athlete's testimony. Derman claimed he'd read this in the court record, but that Pistorius had told him he'd moved cautiously down the passage towards the bathroom.
Derman said he'd got Pistorius to demonstrate how he moved on his stumps. He had even recommended that Pistorius show his mobility to the court to show he could not "run".
When going down the passage, the athlete put one arm in front of himself, holding the gun with the other behind him.
"Are you happy now?" Derman asked, after demonstrating Pistorius' stance.
"Those sarcastic responses aren't doing your credibility any favours," said Nel.
Nel asked if because Pistorius had a gun ahead of him, he intended to shoot, and Derman agreed, but only for the purpose of protection.
"If he came across a stranger or intruder, I suppose he would shoot," said Derman.
He said he believed that a second startle sound - what Pistorius believed to be the closing of the toilet door - further sent Pistorius into a fight or flight response.
Nel asked if Pistorius was still evaluating his surroundings at this point, and Derman said he was.
However, he said he couldn't comment on whether Pistorius had seen anyone in the bathroom, and objected as this wasn't part of his expert testimony.
He was also unable to say what Pistorius was going through physiologically at this point.
All he could say was Pistorius was extremely frightened, and turned towards the toilet door at the perceived danger.
Nel accused him of manipulating the facts of what happened that night to fit with his interpretation of what startled Pistorius.
Derman denied this.
The third startling noise for Pistorius was the sound of wood moving, which the athlete said in his own testimony was most likely the sound of the magazine rack moving in the toilet cubicle.
Derman said this culminated in Pistorius firing through the cubicle door. With further prodding from Nel, the doctor also said that Pistorius fired at the sound.
Nel put it to the court that Pistorius fired at the person inside with the intention to kill, and Derman said it was possible that this was the case to neutralise the threat.
Nel then asked for the case to be postponed to Monday so he would have time to consult with a state psychiatrist to prepare for the remainder of the cross-examination.