There's no doubt in my mind that the silver car was speeding, and when they saw the white car backing out, they laid on the horn and braked to avoid a collision. And then they kept on the horn, probably annoyed that they had to slow down, and that the white car didn't change direction and pull back into the driveway out of the way.
The white car's vision was likely obscured by both the tree and at least one parked car, And they'd especially have a hard time seeing the speeding silver car because it was traveling at least 45 MPH in what is likely a 20 to 30 MPH zone, so if the white car had checked for traffic, they still may not have seen the speeding silver vehicle because it entered the "danger zone" after they checked, but moved towards them at an unanticipated speed. We can't really know if they looked, looked well enough, etc.
So we have an impatient speeding jerk and someone who clearly didn't really check well enough before entering the traffic lane.
But this is a residential street. People have to be able to get in and out of their driveways. So the proper and safe thing to do is to drive at a prudent speed, and watch for cars, kids, pets, etc., that might come out from the side into your lane, and then be courteous and slow or stop to let them in or out, or whatever. For traffic to work smoothly and safely, people have to follow the golden rule as they drive and not be so selfish.
As my old drivers' ed teacher said, back in '74 or so when I took that class, it takes TWO mistakes to cause a collision. He also said there's no such thing as an "accident". Someone, usually two people, must screw up. So call it what it is: A wreck, or a collision, but never call it an "accident".
Both drivers are almost always at least partially at fault. One guy makes a mistake, and the other guy isn't looking, is driving too fast, etc., and is unable to avoid the other guy. This is why they teach "defensive driving". The idea is to be watching for and anticipating the kinds of things that are likely to unfold ahead of you. And thus, you should be driving in such a manner that you can avoid the typical things that might happen. None of this should come as a surprise to you. Wouldn't a reasonable person expect that someone might back out of their driveway, and perhaps not be able to see very well when doing so? You don't have to be a brain surgeon to expect such things.
The speeding jerk could have hit a dog, cat, child, etc., that darted out from between the parked cars. He may have had the right of way, but he would still be at least partially at fault, and likely could have prevented the tragedy by driving at a reasonable speed and looking for (and expecting) the typical events for a residential area. The video from this camera capture would have hung him in court because his speed could be easily calculated by distance traveled per number of frames, knowing the frame rate. If cited for speeding contributing to an accident, he or his insurance would have had to cough up at least part of the damages had there been a collision.
So, yeah. You shouldn't back out into traffic if you can't see that it's safe to do so. But you should also not drive so fast, and be such a jerk about it if someone (heaven forbid) actually wants to exit their driveway. I live on a far-too-narrow, far-too-busy residential street that has, unfortunately, become a major thoroughfare as the town has grown. People often speed through the area, and when I'm driving, I fully understand their side of things. But when I'm trying to park or get out of my driveway, then I fully understand the side of the residents.