I find animal body language a lot easier to read than humans' - I've been around animals since birth, but didn't have nearly as much interaction with people (well, not ones that weren't aggressive/abusive/neglectful at any rate - so I'm great at working out if a human is seriously thinking about lashing out physically, not quite so much at whether I'm wasting my time asking for a payrise or if they actually like me).
DP didn't have that experience or knowledge, so couldn't tell whether a dog was happy, relaxed, excited, uneasy or feeling threatened. So he'd feel more like you - because a dog would be speaking an entirely foreign language to him and he'd be unable to communicate back..
Personally, I have a maximum size preference in dogs which reduces the scope of harm one could cause in the event of illness, injury or fear - or just bowling me over in excitement that I was there. But the principles are still the same - understanding body language, understanding needs and knowing when to say 'Nope', which includes not exacerbating the situation so that attacking is a viable/the only reasonable response in the mind of the animal.
The trouble comes where people have no idea about animal behaviour or health and put them into situations where the wild animal response has no choice but to come out, instead of the overlay of domestication and socialisation we've managed to create on the surface.
Many of us in exceptionally stressful situations are surprised how we respond, whether it's fighting, running like fuck or freezing - that's where our animal instincts have broken through the veneer of respectability. Animals are no different; we can be a friend, a threat or food, depending upon what we tell them. A cow will kill you because you're a threat to their calf or because they're scared and you're in the way. A horse can kill you because you're a threat to them or they're trying to get to run away. A cat will fight like a demon because you're a threat to them and they can't run away, any bigger and you'd be food if you triggered their instinct. A boar would kill you in the right circumstances, as would a bear.
None of this changes the fact that other humans are the main threat to people in comfortable lives - but these are animals. They're not people. So you treat them as dogs with the awareness that underneath the snoring on the rug or yabbiting on about the squirrel outside, they are an animal with no greater intelligence than a preschooler, just with much bigger and sharper teeth.