My father had demensia in his final months - similar symptoms to alzheimers, but different cause. Actual cause of death was pneumonia.

Anyway, pneumonia was a result of his aspirating into his lungs. Aspiration was a result of his intense agitation when he was fed something he didn't like. Agitation was a result of demensia and a resulting inability to handle disappointment in a normal manner.

The line might not be a straight one, but the cause/effect is likely legitimate.

Care givers in a situation like this have a virtually impossible and thankless job. I'd let the issue die along with him.