“You see how irresponsible it is to try and be an expert in area that you’re not?” Nel asked Dixon, a qualified geologist, in the High Court in Pretoria.
He was the third defence witness to testify in Pistorius’s trial.
The paralympic athlete is charged with murdering his girlfriend Reeva Steenkamp. He shot her through the locked toilet door in his Pretoria home on Valentine’s Day last year, apparently thinking she was an intruder.
Dixon, whose evidence-in-chief was led by Barry Roux, SC, seemed to corroborate testimony by Pistorius that he kicked and battered down the door using a cricket bat to get to Steenkamp.
Nel criticised him for drawing inferences based on photographs and reports compiled by other experts. Dixon had not furnished the court with a report on his own findings, but instead referred to notes he had made on sheets of paper.
He testified on a recording of gun shots and a cricket bat striking a meranti door, furnished to the court as part of his evidence, although he was not there when the tests were conducted.
During questioning by Nel it emerged that Dixon did not know whether the music producer who recorded the tests had any experience in recording the sounds of explosions or guns. Dixon also knew nothing about the sound equipment used.
Although Dixon was not present when the post mortem was conducted on Steenkamp, he testified about the bullet wounds and injuries caused by wooden splinters. He said the bullet that hit her hip caused her to fall backwards.
Nel disputed this, saying: “It only happens in the movies.”
He asked Dixon to provide literature on this when he returned to the stand on Thursday.
At one point Nel referred Dixon to a page in the post mortem report pathologist Prof Gert Saayman conducted on Steenkamp.
According to Saayman’s report bruises on Steenkamp’s buttock were caused by bullet fragments. Dixon however told the court that the bruising occurred when Steenkamp fell against wooden magazine rack in the toilet cubicle.
“You looked surprised. You never saw that?” Nel asked Dixon.
“You, Mr Dixon, just made an inference without reading the document.
“The most irresponsible thing is you refer to a document and don’t ever read the full report.”
Dixon admitted he was neither an expert in blood spatters nor ballistics, despite having testified on this for the defence.
Saayman and ballistics expert Captain Christian Mangena were both in court. Mangena at times seemed amused by Dixon’s testimony.
As testimony on Steenkamp’s wounds was heard, Pistorius bent down and covered his head.
The trial will break from Thursday until May 5.