Nel had questioned tests Dixon, a qualified geologist, conducted on sounds made by a cricket bat hitting the reconstructed toilet door, a gun firing, and visibility in Pistorius’s bedroom on February 14 last year, when he shot and killed his girlfriend Reeva Steenkamp in his Pretoria townhouse.
He is accused of murdering Steenkamp. He shot her through the toilet door, apparently thinking an intruder was behind it and about to emerge and attack him.
Nel said: “All you did is hit with a cricket bat. For the visibility test, you used your own eyes.”
He moved on to the fibres of the white socks Dixon said came from paralympian Pistorius’ prosthetic legs, and which were found on the toilet door. Nel asked whether Dixon had physically touched them during his analysis.
Dixon said he did not examine the socks under a microscope, and used induction from seeing a photo of the socks Pistorius had on his prosthetics the day Steenkamp was shot.
Dixon said on Tuesday the fibres were found in the varnish of the toilet door Pistorius stated he kicked to get to Steenkamp.
Nel said: “Are you saying ‘I saw a photo of the socks and made a deduction’?… Have you ever held those socks in your hand?”
“I did not physically touch them… I did not pick them up,” he replied.
Nel said: “As an expert, it makes me concerned.”
Dixon, following further questioning, said he had not received blood spatter training.
Dixon could not say exactly which splinters from the door landed where and when, as Pistorius struck it with his cricket bat to break it open.
Nel moved back to Dixon’s career. He said he had given testimony in court before.
“I view myself as an expert. My testimony has been accepted in court on a number of occasions.”
Nel asked Dixon, who was with the police’s forensics laboratory, when he last did a proficiency test. He replied it was either in 2011 or 2012 as he was no longer with the forensic services.
“For an expert, you are being very evasive,” Nel said after further questioning.
Pistorius has pleaded not guilty to the charge of murder, and two three charges of contravening the Firearms Control Act.