I don’t own one, but it always seemed kind of silly to me. If I wanted a SAK to be able to hang from a carabiner, I would just put one through the split ring.
I've had the split rings work their way off things before, which is what had me wondering about this one.
I’d be interested in learning more about what happened if you’re willing to share, as I’ve always considered split rings (at least good quality ones like Vic provides) to be a fairly reliable means of attaching things.The only failure I can recall from personal experience involved a split ring that was overloaded to the point that it failed structurally. Even then, nothing was lost, but the split ring was trashed.
One of my squadmates hung his Vic off an old style flat spring-clip (as pictured above) which was clipped to his webbing. A couple of times he noticed that the swinging of the SAK meant the clip worked its way under the open end of the ring. One day he went to use the knife and found the clip was hanging empty.
Other occasions I've heard about is where the SAK has caught on something, during physical activities, and that has pulled (or snapped, burst, whatever) the split-ring apart, again resulting in the loss of the SAK.