If it were stated as a hypothetical then I would say it is "academic" for the reasons given by @Edwin. If it were a claim then I would say that the reasoning behind the claim is "specious"
having deceptive attraction or allure
having a false look of truth or genuineness
"moot" generally implies the claim is not relevant due to factors outside the claim itself, for instance,
"If I was stranded on a desert island with no food, I wouldn't kill animals to eat even if I was starving to death."
would be rendered moot by being thrown into a prison for life where vegetarian was the only option, or if all food animals went extinct. It may or may not be true, but it is no longer important because there is no choice but to be vegetarian.
EDIT:
I believe the choice would be "unfalsifiable" which would apply when the situation were actually completely impossible to test due to its nature. It would not work for the 'highly unlikely but possible' case though.
If the opponent is known to be adversarial then you have more leeway in saying something is unfalsifiable. As in, you can take into account that the person may actively try to reinterpret the statement were the situation to occur. For instance "I can beat up the best guitar player in the world." could be called unfalsifiable if deciding who the best guitar player were left to the other person. The person can always claim whomever they failed to beat up wasn't actually the best guitar player and they think someone else is better thus indefinitely delaying the testing of the hypothesis.