Cables stretch when they are used to pull heavy loads. When something breaks, the cable releases its tension like a big strong rubber band, and it will come flying in the direction of the attached ends. Chains don't do that. They stretch, but they just drop when the tension releases. Chains are the thing to use if you are going to abuse.
That is why you never want anyone within striking distance of the cable when you are winching a heavy load. The driver needs to be ready to duck below the dash... it happens very quickly, he might not have time.
Hook failures are pretty common. They should always be affixed to the load with their open end pointing up. That forces the hook to fly down if it bends open. It also encourages the cable to snap down into the dirt, rather than flying back at the truck and the load.
Cable breaks that pass through a snatch hook will always fly to the outside of the bend. You never want people to be there under any circumstance... and yet that is where spectators seem to always stand.
-Chuck