For the record, my fastest laps have been after some jerkoff makes a bad pass, or rearends me, spins me out and doesn't appologize. It usually results in however many minutes of very focused racing from me so that I can get back in front, not to hit the other driver but to point out how much of a better driver I am.
In Motorcycle racing.. (Which is somthing I do) one of the first things that is told to new riders is:
#1. It is always the responsibility of the person MAKING the pass to make a safe pass. The person being passed is NEVER under any circumstances in any way expected to make it "easier" for the passer to get around. However, you can give a corner if you wish. This rule of course is out the window if you are NOT on the lead lap and the person passing you is. In that case you are not just expected but obligated to yield to the passing car.
#2. I'll give you an example of a real life occurence that happened to a good friend of mine a few years ago. He was holding a line about a foot off the bike in front of him, waiting for a a decent passing corner to get around the bike infront of him in a safe manner. Going into a particularly fast sweeper the lead bike..well we don't know WHAT he did but he shaved speed, left the racing line, and almost immediatly came back. However when you are moving at 120mph you are going almost 80 feet per second. In the time the lead bike shaved speed, left the line and tried to come back, my friend had moved into his position. The result was the lead rider and my friend colliding, luckily they both low sided and simply slid off the track.
The Lead rider was at fault plain and simple, the second rider held his line, as he should have.
Judging by your story I'd say it's nearly the same thing and the lead car was at fault. However you have to understand that ALOT of the people online don't understand basic "Laws" or Rules of conduct on a race track, and when somthing like this happens they generally react negativly instead of accepting responsibility.