Director Liz Garbus states in her interview with HBO that the central mystery of her exemplary documentary is that ordinary people can do monstrous things. In Diane Schuler’s case, it was driving the wrong way on a New York parkway and crashing head-on at 85 mph into an oncoming car, killing herself, her daughter, three of her nieces and three men in the other car.

I don’t think that’s it.

The extraordinary thing that’s documented in some detail by her film is that when ordinary people do monstrous things contrary to what’s perceived as their essential nature, then some people — often the ones closest to them — will refuse to accept it even when all the evidence points to the same awful, yet obvious, conclusion.

People will believe what they want to believe regardless of the technology put into play to convince them otherwise. If you don’t think that judgment has relevance to pretty much every crisis humans face on the planet right now then you’re clearly not paying attention.

There’s Something About Diane, like all docs that I admire, doesn’t flinch from anything it uncovers. And yes, you may just want to look away from the tragedy. But, don’t.

Playing through the month of August on HBO.