Here's a picture of my left hand that took a quick hit as the blade of the folding Kerambit passed by doing high speed dual hand flow drills the other night.
Notice in the closeup photo, how the cut is not straight, but arcing in two directions as the blade passed through in the flow drill on it's way to it's target.
It happened at 9:30pm Friday night. Instead of waiting at an emergency room for several hours to get stitched, I had a medical friend of mine bring his suture kit to the house and he sowed me up at the kitchen table. Three nerve block shots below the thumb, shots to and into the wound channel, and he was gone in an hour. It bit pretty deep, didn't want to stop bleeding, and nicked a tendon, cut a bleeder, but all in all, it will be back to normal with no permanent damage or loss of function.
I got lucky, as unlucky as it was to happen
Now, I can hear some saying, IDIOT, for using a live blade to train speed flow drills, let alone any training with a live blade to begin with, or some such.
Let me just make one thing clear to those with that thought process:
You need to have the confidence to use the tools you carry in the manner in which you train to use them. If you are serious about training for the real fight, use the tools you'll be using to train.
Ya, it's dangerous practice, obviously, as the photo shows here. Lots of things are dangerous, it's no reason that as your levels of skills increases, and the drills are down pat from years of training them till they are subconscious, that you should be afraid to use the tool you carry for SD in the manner you may need to use it on the streets should you need it.
I'll not stop practicing with the live blades due to this setback in the future. Moving them around your person dynamically is good at keeping you honest with your skills level and what you are potentially looking at should it happen in the real world.