for you guys w/manuals and no parking brake... I've had 2 instances with different vehicles being in first gear and rolling the engine over backwords. One was a ford ranger and one was a mustang. Both rolled back out of a driveway all along chugging the engine backwords.
I had to start bringing a wheel chuck with me to set behind a tire on anything more than the slightest incline. After sitting for a few the compression will slowly seep out of the cylinders and cause less force to turn it over. By morning, it could be in a large shrub or the yard across the street.