Well yes, they were both shooting with a slip cuff model 2 (might of been a quick cuff), but that was not what was interesting, They were both shooting using a very unconventional sling setup.
Im gonna try to go back and grab a screen shot of it, but basically they were doing something that I have never really seen done before, but they seemed to be able to use the sling to lock the weapon down even more than the already solid position they were in using a front/rear supported shot with both a bipod and a rear bag (rear bag hold grip).
I've never seen anybody who was shooting from a supported position and using a rear bag also use a sling supported hold at the same time since all it would do is reintroduce the shooters influence onto an already stable support that the weapon has being supported by the ground and not having contact with the shooters weak hand at all.
But what these guys did was move the front sling mount using a rail qd sling attachement mounted on a 45 deg. cant and mount it way way back on the rail, much closer to the shooters body than you would ever see a conventional sling attachment. So what it did was basically add another point of stabilization for the rifle by creating a nice tight triangle with a point of contact from the rail to the classic cuffed sling part of the guys upper arm.
I realize its proably impossible to follow my description so im gonna try to grab a screenshot, but from the way they both immediately cuffed into their slings it was obvious that they were both familiar with this technique of shooting, and from watching every other ocmpetitior go to the line, nobody else even considered using a sling of any kind. and these guys were the only shooting pair in the entire match to both score hits on the final target.
.....
I grew up relying on the use of a sliing supported hold on my weapon whenever possible using a cuffed sling as opposed to a simple hasty and still really enjoy that method of shooting, so I was excited to see this new (to me at least) integration of the best of both worlds.