When I first pondered this question I thought yes tobacco companies should help dairy owners with security measures, ethically anyway. I think the smart thing to do would be to only allow tobacco sales via vending machines in outside locations similar to ATMs. Dairy owners could still charge companies rent and power to have them attached to their store. The driving force for this change would probably need to be the government through regulation.
When I thought a little deeper for other products that can have negative impacts I couldn't easily think of many manufacturers that take much interest in the effects their products have on retailers or end users. Their are requirements for manufacturers to design plant and equipment to be safe in HSaW but does this pertain to the safety of those in the middle of the supply chain? For example do the manufacturers of aerosol spray cans do much to ensure their product is used as intended and not used for getting high on? The only thing I believe they do is possibly help with lockable display cases which I think is a regulatory requirement. Do gun manufacturers do anything to stop break ins of gun retailers?
Is it time for WorkSafe to consider a prosecution of a dairy owner for failing to take reasonable practicable steps to protect workers from harm by removing some of the risk of robbery by removing tobacco from sale in their premises? They took a case against Ministry of Social Development in Ashburton under the previous Health and safety Act.
It is time for the government to regulate the way tobacco can be sold.

I take your point Phil, but the fact is - unlike spray cans - the government already places a truckload of conditions on the sale of cigarettes to protect the health of potential purchasers. And one of the disincentives to purchase that it uses - excise duty - is what created the black market and made dairy owners vulnerable in the first place. Add to this the fact that most dairy robberies - including this week's near-fatal stabbing - are committed by people too young to legally purchase cigarettes, and I think we have a clear case of the government creating a risk and requiring dairy owners to manage it. It's easy to say they should just stop selling the things if they can't protect themselves, but dairies operate on very small margins, and for the owners I spoke to it was a commercial necessity. One of them told me he'd be happy to stop selling cigarettes, but only if other dairies had to do the same, because otherwise he'd lose a big chunk of his customer base.

While visiting Europe I liked that I could only purchase cigarettes through a tobacconist or from a vending machine inside a dairy/pub, perhaps for every bodies safety this is the what NZ need to do.