E-Collars as "Torture"

There was a segment on one of my local news broadcasts last night about a father who is now charged with torture because he put canine shock collars on his children. According to the broadcast, he thought it was funny and got his jollies chasing his kids around and threatening to shock them or actually doing so. But this raises some important questions in my mind - is it considered torture because he wasn't training his children but just shocking them for the hell of it, or because he put the collars on humans rather than dogs?
The report even noted that "it wasn't specified if the man even owned a dog" . . . which seems to intimate that it would have been perfectly fine if he had put the collar on his dog and shocked to his heart's content.
So just what is the dividing line here? Is it acceptable to shock (or "stimulate," as the manufacturers of the e-collars like to phrase it) one species of animal but not another? (Yes, we are indeed animals.) Or is it acceptable to shock for the purposes of training but not otherwise?
Unlike a lot of positive trainers, I actually do see a (limited) place for shock collars in training. Some behaviors are so potentially unsafe that the temporary infliction of some pain seems a reasonable response to avoid worse consequences - avoiding rattlesnakes, stopping chasing of deer (for which dogs can be shot), stopping chasing of cars. Aside from the rattlesnake training, it would be less painful and just as effective to keep the dog on leash or confined in a fenced yard, but in reality this isn't going to happen a lot of the time.
What caught my attention in this news piece was the blithe assumption that the shock collar was perfectly fine for one species, but "torture" for the other. If the piece had been presented differently, emphasizing that the collar was being used solely for entertaiment of the male (it doesn't seem appropriate to call him a man or a father) and not for any even marginally legitimate purpose, it wouldn't have struck me this way. But the fact that it was presented the way that it was seems to say a lot about public opinion.
I subscribe to Gandhi's excellent quote (which I may not have word-perfect) - "A nation will be known by the way it treats its animals."