It sounds to me like two forms of payment were declined. I've had perfectly good credit cards declined because the credit card company cranked their security up too tight and I was 100 miles away from my usual haunts without notifying them in advance. And, I can understand the check not being accepted.
Still, that's no excuse for grabbing the delivery guy by the throat and wolfing down the food.
Dementia is definitely a possibility given his age and prior assertive station.
That happened to us in Laughlin, NV a couple of years ago (200 miles from home); wifey was buying a pair of shoes at the Outlet Stores and the Discover card got declined (even though their history should have shown we've been there a half dozen times).
The sales clerk said this has become quite common, and a thirty second security-check phone call from the store fixed it.
Now, however, if we're gonna be traveling, I call ALL of our card companies...