if you read the comments, you'll note that that was illegal. The shooter took 2 deer with a limit of 1.
First, where in the comments? I went back two years in the comments and didn't see anything regarding its legality, or that he took two deer with a limit of 1?
Why do you think the limit is 1? For all I could tell looking at the video it could be here in Virginia (where we have no daily limit for does). From the sound of it, they were certainly in the Southeastern US.
And I know of no law that says you can't take 2 with 1 shot. I've done it twice with a .280 Remington. Heck, its not deer, but the Ruffed Grouse Society actually has a special pin you can get if you have a witness to your taking two birds with a single shot. How is this any different?