Ruggs rear ended the Toyota. If you look at the back of the Toyota there seems to be minimal damage to the rear end, so it seems she was probably moving at the time of the collision, which would explains why she didn't die from the impact.
Does it seem odd a car with this amount of damage should catch on fire? Maybe part of a possible defense? No, the crash didn't kill her, the fire did, and it was because so and so fault with the car so Ruggs isn't entirely at fault? (just making wild speculation about a possible defense)