Final answer:
Expert opinion and rigorous training may suggest that well-socialized and trained dogs are predictable and possibly safer when off-leash, while domestication practices and certain cultural norms support the idea of dogs behaving safely without leashes.
Step-by-step explanation:
The question asks which evidence supports the notion that off-leash dogs with their owners are safer than dogs on leashes. Primarily, the expert opinion suggests that dogs that are properly and rigorously trained, like service dogs, showcase behavior that is under control and predictable when compared to dogs that are not trained to such standards, as seen with emotional support animals in the provided anecdote. Furthermore, domestication has guided the breeding of dogs towards desired traits like calm temperament and an ability to get along with others, which might imply that a well-socialized dog could behave more predictably off-leash than a dog on a leash that may feel restrained and act out unpredictably.
Anecdotal evidence of dogs effectively responding to their owner's commands, even when distracted or in unfamiliar settings, could imply that a well-trained, off-leash dog might adhere to its owner's commands for safety. Finally, cultural practices that allow for dogs to live freely yet alongside humans, resulting in mutual respect and companionship, indicate that such dogs can behave safely without the need for leashes.