I mean… Theoretically if she had a strong enough drive train, and the car was overall very heavy, she could absolutely back up again.
However, given the height of the bollard vs the ground clearance of the undercarriage, I believe it would pinch the bumper downward and possibly prevent the car from going anywhere. It depends on how strong the bumper materials are, and if anything from the frame is in the way.
Source: my ass, but it’s my best guess based on studying more crashes than I care to count.
Your ass is probably correct.
Also the bollard was initially pushed down by the rigid frame of the car. Now it is inside the boot. The inside of the boot will be pushing against it.
Now they’re going to call roadside rescue and going to have to explain how they need a crane rather than a tow truck.