- Can you provide a source for your claim?
I think, as a very non-statistician, that there is confusion in terms, partly because Slowvehicle, as someone who knows his stats, is continually bouncing between formal terminology and casual terminology in dealing with those of us who don't know stats.
Allow me to try to decipher:
If your hypothesis is A, then the complement is ~A (or the other symbology that I discovered is out there like A' or A with a horizontal line over the top).
If you choose to define ~A, then you must ensure that your definition actually includes all ~A. In some cases this is easy. For instance, if A is defined as rolling a 1 on a fair six-sided die, then ~A can be defined as rolling a 2, 3, 4, 5, or 6 on a fair six-sided die. For your A of a single, finite Jabba, you can if you like take the time to define ~A, but to do so you will need to define everything that is not single, everything that is not finite, and everything that is not Jabba. So saying ~A is multiple Jabba is insufficient though you seem to think differently.
But there is another problem that looms just as large that seems apparent to me, the casual non-statistician, and it not only looms as large as the definition problem but seems to be the source of much of your confusion.
First, going back to the die scenario, where A is defined as rolling a 1 on a fair, six-sided die, it makes implicit assumptions, and it does this because it is not a universe-addressing scenario. ~A isn't really limited to 2,3,4,5, or 6. It should also include landing on an edge in a crack on the table and landing on a corner in the shaggy carpet and getting stuck to my sweaty palm and quantum-phasing through the table and getting eaten by a goose. We don't include those things in the definition of ~A for the scenario because we have made assumptions, i.e., that a normal outcome will occur. In doing so, we make the statistics manageable, but we have also defined our problem down to an ideal. That is perfectly fine because we are not looking at fundamental universal laws.
With your immortality gambit, though, you are looking at fundamental universal laws, but you are treating it like the scenario with the die. You want to define all the abnormal things out of the problem and then use your calculations as if they apply to the abnormal things.
Ah, well. Best I can do. If it's just a pile of layman mushy ignorance, I apologize.