First, I'd like to say I am not a medical professional in any form, but neuroscience and the brain is always something that has fascinated me. It's a career move I'd possibly like to make one day, so in my spare time I attend open lectures/courses as and when I can, look up research studies in journals and read a lot of brain based books. As such I have built up some knowledge and I've been reading and researching this type of stuff fairly recently, so you're lucky I guess
It's hard to judge because I didn't see it myself, but I'll assume it was a severe hit to the head just above the ear on the side of the head. A little anatomy lesson - the brain is made of the cerebrum (the wrinkly folds on the surface), which is split into two hemispheres - left and right. Each hemisphere has 4 lobes - Frontal (at the front half of the skull, dealing with executive functions such as control, organisation), Parietal (around the crown of the hair, dealing with perception mainly), Occipital (at the back, dealing with vision) and Temporal (underneath the temples
, dealing with memory, language and comprehension).
A hard hit here by a blunt object is likely to lead to what's called a coup injury, where the area around the initial contact is damaged (the alternative being a countercoup injury, where the area on the opposite side of the head to the initial contact is damaged, i.e if the back of your head hits the floor your brain will keep on going even though your head has stopped and the vacuum at the front causes damage). This would likely cause a traumatic brain injury (TBI) of a moderate nature, with unconsciousness lasting over 30 minutes. When the person regains consciousness, a moderate TBI would cause immediate post-traumatic Amnesia (PTA) and some confusion, dizziness, nausea, disorientation, pain and difficulty with speech, to note a few symptoms. The PTA is most important though, as it normally leads to memory loss and a lack of executive function (i.e decision making, organising). Depending on the severity of the injury, these symptoms can last weeks and months, or permanently in some cases. There are also risks from fractured pieces of skull piercing the brain and causing more damage than was already there, or long term from pressure building up inside the brain (such as from a subdural hematoma).
Basically Paul, I'd say it's extremely unlikely she'd have got up, walked in a straight line, hit her attacker, spoke unimpaired and even remembered who she was if the blow was severe enough to knock her unconscious for that long!
Writers do consult medical professionals when writing scripts, but sometimes it doesn't fit the story to do what's realistic. In this case, he would have either had to hit her over the head with a soft toy and then bunged her in the boot conscious in order for her to be fine after, OR if the blow had to have been that severe she would have had no chance of escape.
