That's one plausible explanation. The article linked further down the thread references being struck by an open door.
I think the point I and others were trying to make is that if you leave an SUV in neutral, clamber down from the driver's seat to the ground and then open up a rear door and lean inside to unsnap a child from a car seat the car is likely going to noticeably have started into motion by the time these various actions are underway.
Holding him in her arms, she opened the front door and reached across the passenger seat to grab a bag - but the bag knocked the gearshift into neutral, a source said.
The car started rolling and the momentum caused the front door to push her over. She fell and dropped Christopher.
"She was telling me she fell down with the baby and then the car rolled back on the baby. She tried to pull him, but it was too late.
This was a tragic, horrible accident, caused by a moment's accidental carelessness and the poor mother will have to live with the memories the rest of her days.
Pray you remain faultless without any mistakes, and that you aren't judged as harshly as you judge others.