Humans have judgment, the dog does not. The dog is dead because humans sent it in rather than go themselves. A human would have let go rather than be dragged over the side. The dog was trained not to let go except on command. Result is a dead dog.
Dogs are effective in apprehension due to fear factor. A solo dog can not stand up to a trained human. Its one of the reasons you see the handler stay close to the dogs these days. Years ago doctrine was to send the dog in alone. PDs lost a lot of dogs that way.
Not saying the perp did right, but the most likely answer is that the handler effectively sent the dog to its death needlessly.
I might agree with you but the diffedrence is the guy made a choice and jumped, he didn’t fall.