I was beating myself up for confusing the sufficient and necessary in the first sentence.

The word "must" triggers the necessary.

This example helped me understand:

To enter the bar, you MUST be 21.

o If you are inside the bar--> you are 21

x If you are 21--> you are in the bar

Tiger: Not all liquids are safe for consumption. After all, wiper fluid is very toxic and can cause serious damage to your health if consumed.

Disney: Billionaires can access the US Capital. Billionaires who have funded the Republican Party can have direct say in Congress. All other billionaires have to suck Trump's toes. Elon Musk is a billionaire and can access the US Capital. Elon has direct say in Congress. Elon Musk has never funded the republican party. Elon Musk must have sucked Trump's toes.

Detective: There are people screaming, "shots fired" and hiding in the airport. The cartel leader who was in possession of cocaine is lying on the floor with a bullet wound to the chest. A soldier is standing 10 feet away from the body with a gun in his holster and white powder on his face. My hypothesis is that the soldier killed the leader in order to feed his crippling drug addiction.