I agree with the others, if people are going to have a dog and rabbit try and live together they often get the rabbit and dog around about the same time when they are both young. Thus having the dog grow up alongside the rabbit and learning boundaries from the start. But personally I'd never leave a dog with a rabbit no matter how well trained it was.
A rescue dog that is already grown up and hasn't had experience of small animals will most likely find the rabbit ''interesting'' enough that they may harm it....
I always say...why do you think so many dog toys are small and furry and make squeaky noises? These toys replicate the sounds of a small animal being killed. This is why they are so attractive to dogs, they are predators. So, generally to a lot of dogs, a rabbit will make a good toy....and its extremely dangerous to allow them to be around one another. x