Your link goes to some adhesive backing there, Bro!
Never mind- I think we get the picture.
You could probably tell for sure if you lost a chain link/connector by comparing the busted one to its mate on the other side. Just count the number of remaining links.
If you did in fact lose it, in my mind that's a warning that whatever you've got is
not equal to the job assigned. It shouldn't have "failed" when called upon; thank heavens it happened at a low speed and not on the highway. You might have lost the whole shootin' match at 60 mph!
Being skeptical of the strength and suitability of many chains supplied OEM on trailers, we use some big honkin' chain and the same kind of shackles as pictured above. (No mild steel couplers for us, either).