"Can somebody get salmonella from eating vegan chicken patties.?"
Yes somebody can get salmonella from eating vegan chicken patties. Over the years, a number of food items, that are vegetable based has been recalled, due to salmonella poisoning. In fact contrary to popular myth, there are more cases of salmonella poisoning from vegetable based products, and vegetables than from meat, poultry, and fish/seafood. Processed foods while less likely to be contaminated, has been know to occur.
Salmonella doesn't just come from chickens, but other birds such as pigeons, seagulls, and crows can act as carriers, along with feral/wild pigs. Also rats and mice can act as carriers, and fish/seafood (usually consumed raw or under cooked), has been known to be tainted with it, as well. So contrary to what some state, or otherwise claim about it being a chicken born issue, it's not.