So I withheld my need to comment until we got more information.
Sick, stray puppy? Looked pretty healthy to me... fat, furry... just as a puppy should be.
I'm all about euthanasia. I find it much more humane to euthanize an animal than allow it to suffer, or meet some inevitable ugly end. There are just too damn many of them (spay and neuter!). I'm sure the situation is much worse over there.
I, personally, couldn't violently end the life of an animal that wasn't a threat to me. I've administered euthanasia shots, but that's different from shooting a dog or hurling one off a cliff.
Maybe he felt killing the pup was the best option... but it is sick and twisted that he got his jollies off by throwing it off a cliff, much less filming it.
There are worse people out there, who have done far worse things.
This guy sucks, I wouldn't be his friend, I wouldn't share my skittles with him.
But I'll focus my disgust and hatred on more deserving souls.