I posted this in the long thread below, but it's relevant to this discussion as well.

Note the fence along the tracks with the reinforced concrete posts. It appears the front truck of the cabcar left the tracks, hit several posts and dug in, all while its rear truck was still on the rail or at least ties. It appears the impact and subsequent pivoting of the cabcar pushed the car behind off to the opposite side with great lateral force which explains the rail being pushed out. I'm assuming the older car on the street was that car behind judging by the force involved.

What's interesting is the truck being pushed into the crossing protection in the center median. The median is heavily damaged suggesting the foundation of the gates was ripped from the concrete. This could have provided extra force to pushe the cabcar in the direction it went.