From what I see and read, the part I dont like is the waste and dumping of numerous carcases in a stream. I dont know SD game laws so I'll try not to comment on that.
I have no lost love for coyotes and if they are killed, I dont care if it's a gun or a snowmobile, as long as it is legal. To me, there is nothing more morally wrong in running down a coyote wth a snow mobile than a coyote running down a sheep or calf. IMO, running down a preditor is more "humane" than said preditor(s) running down their game and ripping it apart while it still breaths and struggles. I have a neighbor who lost 30 sheep in one night to a pack of coyotes, so you will see no tears shed from me when I hear about coyotes dying by whatever means. what I dont like about it is wasting them if their hides are worth something, but not really a big deal to me. The biggest deal is the pollution of the stream and the impression it leaves on some toward hunters in general. Kill the coyotes... kill them legal... use their hides if practicle... and dont leave piles of them in view of the general public. If you leave the piles somewhere else, that's fime by me. One last thing..... i read a lot in this forum and others about SSS and you will never find or hear of me practicing it because it simply isn't woth it. It wont help the (wolf) problem and I would only be jepordizing my hunting priviledges and a criminal record doing it. Now with coyotes... they can raise havoc with ranchers and farmers and cost them thousands if they are getting out of control. They are usually reimbursed for wolf kills, but not coyote kills and if I was a rancher with a family to take care of and loosing thousands of dollars to coyotes, you can bet I would do what I had to, to control the vermin. But I doubt this was a farmer taking care of business.
As for the dear, quartering game without gutting them is a fairly common hunting practice and saves time. If you want the heart and liver, then go for it and gut them. As mentioned previously, your tag must remains with your meat in Montana. If you process your kill and find somewhere to dump the remaining carcass, you best not dump the tag with it. If there were deer shot and dumped without harvesting the meat, then prosecute the $%^&**%%$. Once again, dont be stupid about it and dump a pile in a stream in view of the public. I give most of the bones to my dogs and when they are done with them, I throw them back in the woods or burn them.
This is a truely an ugly and unfortunate scene, but it's good not to assume too much and keep things in perspective.
Just my $.02
-Mark