I havn' t, but a doctor in Troy several years ago was checking his wooden ladder stands before season, the ladder broke and he fell about 16 feet breaking shattering his femur. He almost bled to death, could not crawl the 100 feet to his truck and cell phone. They found him a few hours later, but he still has severe pain and walks with a limp.
Another friend fell off a 12 foot ladder stand when he went to sleep and broke his collar bone and a couple of ribs.
The worst I heard of was a 22 year old man that fell out of his climbing stand with a properly installed chest type safety strap. He hung there till he died. They found his knife on the ground, he had dropped it after cutting about 1/3 way through the strap trying to get out.