Yep, we've had raccoons reach through the fence and pull a chicken back out... one piece at a time. My guess is that your predator left because it couldnt reach the rest of the body. We've even had possums reach through a cage with 1/2" x 1" welded wire and pull the feathers and skin off a hapless chicken. Sometimes the silly birds sleep next to the fence instead of up on their roost so we added smaller wire around the pens on the bottom 2 or 3 feet. Hardware cloth is too expensive to do the number of pens that we have so we used chicken wire temporarily. I know that a raccoon could rip it but they havent, so far. Gradually we are rebuilding pens and we put corrugated metal roofing panels lengthwise along the bottom of the fencing to make the lower 2 feet solid.
Im sorry about your hen.
Chel
Im sorry about your hen.
Chel