My worst nut shot? The shot from the needle right before my vasectomy. Sharp needles and testicles are not a match made in heaven.
I can't imagine a dull needle being much better.

Was playing catch with the football and was in a dead sprint looking back for the ball. I ran right into a fire hydrant, left shin hit the side bolt and I came to a dead stop on the top of the fire hydrant crushing my dick and balls on the bolt. Terrible pain in the dick and balls plus my leg was awful. Still have a dent in my shin from it.