In high school gym class we had one day of archery. I am not sure what the arrows were made of, but the bows were the cheap plastic ones with about 15 pounds of draw.
The kid next to me shot the arrow off his knuckle instead of the arrow rest. Next thing I know his hand is impaled on half of the arrow. It was ugly. The arrow had a splinter that caught his hand and once it started it just kept going.
To this day, I refuse to shoot off of my hand. ALL of my bows have an arrow rest. It might not even make a difference, safety wise, but it makes me feel better.
Patrick