I got one this summer that had the entire swivel with mainline leader and hook trailing behind it. Someone was fishing with very light mono main line on a Carolina rig for some reason.
Wow, that circle hook picture is CRAZY. Whenever I gut hook one, I always try to cut the actual hook with about a 30% success rate. If I can’t cut the hook, I’ll clip the line as close to the eye as possible. I was always told they “rusted out” and liked to believe it to make myself feel better. Dang.