Mobs that are one-shot by your pet grant no reputation.
This is not new. If your pet(s) get the kill it doesn’t count for you. So if you’re running legacy dungeons then put your pet on passive.
They changed this, though. You can still loot the mob. You still get XP. You just don’t get reputation. There’s no difference between my pet one-shotting a mob in Shadow Labyrinth with Kill Command and me one-shotting it with auto-shot.
Wasn’t aware it been changed, my apologies. But do you get rep if your pet does nothing? Were you wearing a tabard?
I had the tabard. I just found out that if I kill a single low level mob with a Kill Command, I don’t get any rep from the kill. I ended up dismissing my pet so I wouldn’t be tempted to use it. I discovered this when I used KC on a dungeon boss and got nothing but loot instead of 300 rep.
I think that’s the best thing to do. When I run low level dungeons on my hunter I always dismiss my pet(s).