Yes, quite right, just hunting vs. survival, I won't eat what I don't kill after observing it's behavior before and condition of the carcass after the kill if it is just a hunting trip. However, in setting traps for survival, especially the mangling (killing) variety, you may not have such an opportunity, but must nonetheless capitalize on whatever you obtain, thus the warnings.

Even hunting has it's risks. Sometimes an animal that appears in good health may in fact be infected, and there's really no way to tell for certain out in the field, so you rolls your dice and you takes your chances. Wearing gloves and other protective items helps, but then again, I had a friend draw my knifeblade across my knuckle when I was field dressing my last elk, opening up a 1/2" incision right while I was in the middle of extracting the paunch from the beast. Anything less than metal or kevlar gloves would've done nothing to prevent the cut, so there I was, elk blood and gore up to my elbows, and my thumb bleeding all over. I duct taped the cut closed so I didn't bleed into the animal, finished the job, and when I got back to camp I washed out the cut and glued it shut with superglue. Later that week the superglue started to come off, and the scar healed up fairly tightly, which surprised me some.

Lucky me.

Lesson learned? Don't give your knife to a 60+ year old and let him do the cutting while you hold the carcass open.