When something that happens to me, and it does on occasion, I do a fix similar to smart dog. I take a 9 sweep, 2 mm gouge and cut a long, about 3/4 inch or longer groove. It helps to follow the grain direction. Then, I take a piece of left over wood, ideally from the same area of the stock blank and make an identical cut and save the sliver. I apply some Titebond glue, place it in the groove I cut first, cover with scotch tape and tightly clamp it in place. When the glue is dry, sand smooth. It is visible, but looks like part of the wood grain pattern and no one will ever be the wiser. NEVER fill a hole with a toothpick, it stands out like a sore thumb and will alert everyone to your error.