Sounds like there is an undiscovered group of hunters who eat magpies, gophers and who knows what else, all in the name of eat what you kill.
All of these animals are first headshot so they don't suffer any more than necessary. I suppose that is the ethical thing to do.
This discussion is interesting in that it reveals there are two extremes: one I'd call a "farmer" mentality, of "I don't care how, but the varmint must die", and sometimes, that ain't pretty. The other is the more educated, sophisticated hunter that has higher ideals, perhaps more likely to have a more urban (there I said it, flame on) background.
So, to save a bullet he stomped the magpie. Kind of messy. Raises ones hackles, doesn't it? But is there any real difference? He ended it's misery quickly, isn't that the point. Oh I forgot, ethical hunters never miss. He deserves a beating for almost missing and not making a good shot.
Well, I spent lots of time on the farm growing up, and I say, stop beating up on us farmer types. One less magpie is one less magpie, and that's a good thing.
And to you other farmer types out there, be careful what you post, since you will be pounded thoroughly if you don't meet standards.
Personally, I would have went for a body shot, since the head is a small target at 25 yds. If you used hollow points, it should do the job nicely. And then you wouldn't have to eat it.
Think of all the abuse you would have saved yourself if you had done that. Well, maybe.