Q.what’s consuming tomatoes
What consumed the top third of my green tomato? Overnight, two tomatoes near the ground lost their top third. We have enclosed the garden in a one-inch PVC garden netting stapled to 2×4’s to keep out the squirrels and opossums we see in the neighborhood trees. Assuming these creatures are somehow getting in, what might we do to protect our tomatoes?

Most likely slugs. There is nothing that a slug won't eat, including a tomato plant.
Here is a link on how to control slugs.
https://www.gardeningknowhow.com/plant-problems/pests/insects/kill-garden-slugs.htm