That must be awful course ground meat to allow that large of piece to go through. When I worked as a meat cutter we would find a few bullets when we cleaned the grinder. Tried really hard to find all bullet fragments before it went into the process. But if something has been healed over it can easily be missed. Our grinders would never allow that large a chunk get through.
One time we had a guy bring in a large 4x4 blacktail. It had five .25 pistol bullets between the hid and the ribs. Surprised anyone could hit a deer five shots in a row with a 25ACP

Poacher was obviously not too smart, but must have been a pretty good shot!