I would say “debunked” in the sense that quantum mechanics correctly predicts phenomena that don’t exist in classical physics, and relies on the idea that quantum particles obey a probability distribution, rather than deterministic mechanics.
Quantum mechanics appears to work so well for these phenomena compared to deterministic mechanics that it’s tempting to say that the actual universe is in fact governed by probabilities rather than determinism.
I would argue that all physical models of the universe are just that: Models. We can get asymptotically closer to a perfect description of the universe, but no model can ever tell us the true nature of the underlying system it is describing, just be an arbitrarily good description of it.
HEAT rounds are based on a very thin jet of molten metal melting through the armour. Making the round detonate a distance from the armour can have a huge effect on its ability to penetrate.