You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
It's a decision he says saved his life, and the lives of his wife and two young children.
"There's nothing you can do. If you try to do something, you're going to get hurt, or worse," said Kullman, who was tied up along with his family while the thieves rifled through the house for valuables.
Like many people concerned about South Africa's high rates of violent crime, Kullman puts his faith in high walls, surveillance cameras and electric fences - and passivity if all those fail.
South Africa's annual murder rate has more than halved since the end of apartheid but remains high at around 32 per 100,000 people, compared with a global average of about 7.
So there are still those who go to sleep with a hand-gun under the pillow or in the bedside drawer. "Blade Runner" Oscar Pistorius appears to have been one.
The Paralympic track star, who became the first double amputee to compete in the Olympics in London 2012, was charged with murder on Thursday after his girlfriend was shot dead in his upscale Pretoria home in the early hours.
"The conventional wisdom is that one should not have a firearm and one should submit meekly," Mark Notelovitz, managing director of specialist residential security company Coretac, told Reuters.
"The problem is that when you submit meekly you are then under the control of whoever has come into your home. You never know what you're going to get if you submit."
Police said they had recovered a 9mm pistol at Pistorius' home, and media reports suggest he kept other weapons within easy reach in his house, which sits in the middle of a gated community ringed by three-metre-high walls and electric fences.
A Twitter posting by Pistorius in November also paints the picture of a would-be action man obsessed with security.
"Nothing like getting home to hear the washing machine on and thinking its an intruder to go into full combat recon mode into the pantry! waa," read the Tweet on the morning of Nov. 27.
"I AM THE BULLET IN THE CHAMBER"
Even Pistorius's global publicity machine once chose to compare his speed out of the blocks to a firearm, with an advertisement by his main sponsor, sportswear maker Nike , showing Pistorius uncoiling into a run alongside the tagline: "I am the bullet in the chamber. Just do it."
Although it has a reputation as a violent 'Wild West' society, since the end of white-minority rule Nelson Mandela's 'Rainbow Nation' has clamped down on the weapons in circulation from the armed anti-apartheid struggle.
The ruling African National Congress (ANC) passed a law in 2004 tightening gun ownership, after which many South Africans - in particular whites whose fear of social collapse under ANC rule had ebbed - took the opportunity of amnesties to hand in their weapons.
"The percentage of people who own firearms for self-defence is probably the minority and certainly a lot less than it was 10, 15 or 20 years ago," Notelovitz said. "And the percentage who have a firearm near at hand to use in an emergency is even smaller."
By far the biggest use of weapons among civilians is for recreation and the multi-million dollar hunting industry.
"Most people either inherited firearms or are buying a hunting rifle," said James Cameron, who runs courses for people seeking rifle or hand-gun permits. "Very few people cite self-defence."
However, there are those who, hardened by personal experience and almost daily newspaper headlines detailing horrific violent crimes, still see a firearm in the house as a necessary evil.
"I don't own a gun. I wish I did," said Nthabiseng Xaba, who was robbed at gunpoint by three men in 2008. "If I'd had a gun then, I would have been able to protect myself - shoot those guys and kick them out of my house."