I would think you're guessing right. For most folks, when they use the words "sandwich" and "squirrel" in the same sentence, it usually refers to an incident with a motor vehicle, not a culinary reference.
Growing up, Pigeon was a regular on our menu. My Dad used to raise Pigeons for racing, and the ones that didn't make the cut ended up on a plate. It was more than once we had sandwiches with the leftovers..