He didn’t “suffer” nearly enough.
I think they should have just thrown him into the Crips or the MS-13 side of the lock up and let nature take it’s course.
We put a horse down recently. The vet uses phenobarbital.
It took awhile for the horse to quit gasping for breath, but he was out of it the whole time. Vet just injected more drug. A .22 bullet to the skull is a lot quicker on a horse, but people don’t like to do it. My son had to shoot one of my mares once when we couldn’t get a vet. Quick and painless.