Bad hook set on big fish

Their blood usually clots pretty quickly. I'm glad you're concerned about fish health. As stated, getting them back in the water quickly is always key. I keep a pair of bolt cutters in my bag. Any time a hook is in tissue that will probably be fatal if removed, if the barb is exposed, I'll and cut it off and the barbless hook comes out with no further issues. The other trick, if you are using a single hook, and they get it in their gullet, turn the fish's head to the side, gently reach in through the back gill (the widest opening) and grab the hook eye and pull it through and out the back gill. Now you can take your pliers, look in the fish's mouth and the hook is upside down. You can grab the U bend and pull it straight out with minimum resistance. Of course be careful and gentle doing this. It will save a fish and a dead fish penalty if done carefully.