This is a common argument
To honestly answer: I don't know. I'm assuming that I wouldn't know if rescue was coming. I assume that, if literally no other food sources exist, I realistically would probably wait for the pig to die and then eat his corpse, but I suppose that depends on the demeanor of the pig and self-defense. Whoever lives longer wins I guess, but I also have never gone any length of time without any food options (even if I was rejecting them to fast) - so I really don't know what day ten of hunger-induced delirium and marooned boredom looks like. However, I consider the likelihood of such a scenario ever happening to be essentially 0%.
My turn! It's tomorrow (or some other time in the next few days) and you're hungry. You're considering eating [food X] that has egg in it. But you remember this fact: that baby chicks are routinely thrown into shredders alive as part of the egg industry. What do you do? Do you pay money to create demand for this practice or not? I consider the likelihood of such a scenario, if you regularly eat eggs, to be essentially 100% (If you don't substitute in your favorite animal product and factory farming technique).
What you would do on a desert island has nothing to do with reality.