Yeah, as they stated either he had an old tank with a burst disk or he tampered with and modified so it didn’t work properly.
This isn’t a real issue for concern with properly maintained tanks. Here is another exert regarding this.
In 90F heat a car trunk might reach 150F. You’d have to heat a full aluminum "80" to about 400F to reach even the hydro test pressure, which is 5,000 psi. And the burst disc (which can sound like an exploding Toyota) should blow out at about 4,500 psi, relieving the pressure.