by random chance you might be stuck with a neighbor who would rather rob you during a disaster than help you.

A natural disaster ties together the fates of everyone living in the area. When law and order break down, the people living nearest to you are the most important guarantors of your own safety. Attack or hurt your neighbor and you've only made yourself less safe from outsiders.

All this to say the neighbor would have to be particularly stupid, short-sighted, and sociopathic. Or have a foolproof survival or evacuation plan. Other than that, your survival and co-operation is in their best interest.