WOW.... i have used s-hooks for about 8 years, in several 30+ storms and NEVER seen one bend (I sail a Tornado squartop sail)
Start of the 2004 C-100, coming out of Galesville into the West River. Lots of carnage, we had the jib furled. As soon as we got to the river from the harbor a gust hit, and we heard a sound like a gunshot and suddenly the mainsheet system was no longer attached to the sail. We noodled across the river until we got into a small protected cove and we ditched the straightened out S-hook for a shackle. Continued on and ultimately won the race.
In the pic below, the red and white sail is us on our way to the cove - notice the sail is about 90 degrees to the boat.
I'm sure it doesn't happen often, but I don't want to chance it on a distance race anymore.