A few years ago I used a 16" long push block to rip a 4" long piece of stock. The front of the block dipped into the front of the blade way before the workpiece was near it. The blade grabbed the push block by the end grain and threw it at the shop door. The block weighed about 3 pounds. It left a mark. Luckily I was out of the line of fire.
Since then I have made my push block from Balsa wood. It will not come flying off the blade. Made another one with styrofoam and it works great too.
But those are big and I still have a smaller Pine push block that I use sometimes. Seemed like the right move for trimming Ebony pegs. Wrong, I now have a couple of little marks on my palm. Those will heal in a week.
Time to find some more Balsa.