Past, perfect?

I heard a few years ago a story that amazed me and made me question how much we know about the people around us.
In my home town, next door, used to live an old couple, alone. Their son was in Italy, at work, for more than 20 years.
I grew up with them, as they were friends with my grandmother. They loved me a lot, always gave me sweets, baked cookies, let me play around their house with their dogs. The old man used to teach me how to count in German an other words.
I used to think of them as my other grandparents. I was actually sad when they died and I always kept them in my mind with love and respect.

One day, I was at my aunts and we were drinking coffee, smoking. Somehow, we started talking about how tragic their death was (they both died because of alcohol) and started thinking how good people have nice deaths.
Then, I asked my aunt why they had such a painful death, because I saw the as nice people.

The story starts when their son was 15 years old.
I rushed my self into the story, I am sorry but I have to clarify a few aspects.
The old man used to be a security colonel during the communist period in Romania. Romanians will know that aspect was important, because he had influence in other state structures.That also meant that he was a person that will spy on neighbors and report them to the Communist Party. That also meant that you will disappear over night in a black car,never to be seen again, if you talked about the system, religion...
Getting back in the story, the old lady used to have a lover, outside of the marriage. That guy was a family friend so they could hang around easily.
Suddenly, the other guy dies. Both families were at the barbecue, and the guy get's killed by the family car.

Reality : The kid killed the man his mom was unfaithful with, ran him over with the car.
What the police and witnesses told : the kid wanted to learn how to drive and the man was sleeping in the grass, he didn't see him and ran over him.

As a conclusion, they both died from alcohol, their son returned from Italy, with a drinking problem, sold the house and disappeared.

What we actually know about people around us?