I had the experience of cutting a piece of stock, and it got trapped between the fence and the blade. It wouldn't matter except that the wood lifted slightly, and that caused an off angle into the blade. Consequently it binded, and sent a piece of wood flying into my stomach at about 50 mph. Okay maybe it was 40, but the speed was irrelevant. What did matter is that it was painful, and forceful enough to leave a welt and scraped the skin. If it wasn't a square ended board, but rather a sharp pointed one, it would be of even greater concern.