Halal requirements for slaughter are almost identical to those of kosher.
I'm sure they aren't always implemented properly.
If you buy from a halal butcher, they probably are. If it's Dad buying a lamb for a family feast, which happens continually, you are guaranteed a mess straight out of a horror movie.
Have you ever seen animals slaughtered? I'm a farm girl; I have. It's not a job for amateurs.