It depends on the species. The worst is the mako that has excellent eyesight and can snap at you unexpectedly as your hand comes down the wire.
The problem isn't just the bite it is infection.
A friend cut a shark loose went to the other side of the boat to cut another loose. The first angler put the rod in the holder and left the cut wire hanging into the water. The second shark went around the boat to where the first shark was cut loose. When my friend reached down to cut it loose, it wrapped the wire that was hanging in the water, and unexpectedly pulled his hand down with the wire. He got 27 stitches from the upper teeth of the shark. When I talked to him he had his arm in a sling and had been shot with just about every antibiotic the hospital.
If you get your cutting hand caught between the shark and the wire when t rolls, and the shark turns to bite your arm or shoulder, you have to take your free hand and put it between the sharks upper jaw and snout to hold it off until you get your other hand free.
Usualy it is not a problem except the more you do it the closer to the hook you get. I have cut loose over 700 big blue sharks in one season. Now because of so many cod trips I cut loose 100-300 sharks a season.
But like a baseball player, if you play the game long enough, you will get hit with a pitched ball. I always have that in the back of my mind. - Tom