How do you know it didn't happen in that collision?
Because the damage from accident is all on the left side of the car.
The further 3 images is a dent in the centre rear of the vehicle, with obvious impact right in the middle, dinting it in. The grey plastic is the boot casing / boot door.
The bumper is completely undamaged, with the damage located under it. Would have been some side impact to cause it to crumple like that whilst everywhere else in centre-line of the car unaffected.