I am puzzled as to why OP has so confidently assumed that the (by her own admission, "lovely") owner is a bad owner, simply because he was drunk? I don't drink myself, but most people I know do so, to excess sometimes, and I have never before heard anyone claim that drinking in the presence of your dog is inappropriate? Loads of people take their dogs to the pub; to other social occasions where drink is involved; or drink in front of their dogs at home. Is that wrong, or the mark or a bad owner?
I am not sure whether the fact that the drink that the man was consuming was cider, and that he drank it from a can, was, in fact, the issue? I really hope I am wrong about this, but I wonder whether OP would have been so concerned if the drink had been champagne, and the owner had summoned his butler to bring it to him in a crystal slipper?
I love dogs myself, but I agree that dogs of vast size and strength are too much of a risk, sadly. I would rather all healthy dogs, including my own, were PTS today than that a single human child lose his or her life in a dog attack. And however well trained, no dog can be 100% guaranteed by its owner because it may suffer from behaviour alterations due to a brain tumour or dementia; may react unpredictably in extreme fear or pain; be startled while asleep; etc.
What I abhor beyond measure, however, is when fear of dangerous dogs is used as an excuse for publicly spewing disgusting bile-filled prejudice against the working classes.
(As it happens, my friend's got XL bullies. She's a professional with an Oxford degree and a big house and all the other things people on here tend to admire. And she has her dogs for the same reason I imagine loads of people do, rich or poor. She likes the breed and they bring her pleasure. She does not own them maliciously to hurt or scare. Nor do the vast majority of owners I am sure)