I posted the picture of the bolt you are discussing.
You guys know more than I do. All I can add is that one of those shear bolts snapped when I winched a dead tree out of the woods. It hit a standing tree, resistance was greater than the shear bolt could stand, and SNAP!!, the bolt protected the winch. Luckily, I had another one in the truck, swapped the broken one for a new one, and continued winching. My wet backside did not affect the winching one bit but I keep a small tarp in the truck since then just in case it ever happens again when the ground is wet.
Sorry, no pictures of dead tree and certainly not of wet backside.