My husband is a Vietnam vet, my BIL is a Vietnam vet, and I know loads of Vietnam vets. I cannot think of a single exception to V-vets having major issues with authority figures, including doctors. As a group, it seems to me that, to a dangerous degree, V-vets resist getting healthcare.

Also, I've noticed that most V-vets have a built-in belief about 'manning up' to excess...for example, my husband will be thirsty on a hot day, but will flatly refuse to drink water because 'in Vietnam we had to ration water'. Well, Vietnam, for my husband, was 47 years ago. But he still carries the brainwashing he received with him- in full force.

From your description, I'm pretty sure your neighbor has PTSD, just as most Vietnam vets do. Their minds were insidiously bent during that war. It's easy to judge, but let me tell you...those guys' heads were seriously messed with.