try explaining to an insurance company why you were too close to react to them braking hard. if you rear-end somebody, you are never going to manage to shift blame to the car in front.
He told me how this guy would just blast through red lights and jammed traffic without even looking to see if anyone was coming. So my bud asked this person why he does that and his response was along the lines of "Well since I've got such a crappy car, no one is going to want to hit me since they'll definitely have a better car that they won't want to crash into me".
WTF, seriously what the hell is this guy thinking? What if (god forbid) there's another driver around who thinks like that?
Its very simple, unless the driver in front can find a very satisfactory reason why they suddenly had to brake sharply on a straight piece of road they are going to be entirely responsible for the vehicle behind failing to stop in time and ending up in the back of them.
Since when was that the case? Even if the person in front brakes as hard as they can deliberately, causing you to pile into the back of them you will still be held at fault. You're supposed to drive with a safe gap between the car in front for a reason so that doesn't happen. Its your fault if you find yourself in that position, one which is easily avoidable by not driving so close.
If they did it deliberately they are not going to say that outright (although I wander if it would change the outcome...), all they have to say is they saw something on the road.
If that's what you really think, you'll be in for a shock if you do actually hit the back of someone... regardless of whether or not they brake test you.
I think Alex is right - If someone infront of you decides to brake (hard) on a perfectly straight piece of road with no reason, then surely it'd be there fault. There would be witnesses and you'd of course ask the all important question - "Did you see any reason why this car would have needed to brake?".
in the end it will be your story against his or her story.
you cannot certainly be sure which is true - so you have to rely on the facts.
if you are the one who rear-ended the other car, you are at fault. simple as that.