Sorry to hear.
I have had the same thing happen except I heard the car slamming on his brakes and I was able to get out of the way. They hit the car that was in front of me at about 10 mph. I learned to keep it in gear a long time ago and I also never stop behind a car, I am always very close to the lines on the sides of a lane. I hate seeing all these riders stop 2 feet from the car in front of them, right in the middle of the lane. You are just setting yourself up for a no escape accident.
Hope everything works out.
"Beware of the lollipop of mediocrity. One lick and you'll suck forever!"Brian Wilson