Back Pain Tips

(I’m in the UK)
Last Christmas my brother’s car was hit by a woman who pulled out of a slip road onto a main road without looking. She hit him head on and his car was totalled. My mother who was in the passenger seat was taken to hospital by ambulance, and found to have a broken sternum. The woman in the other car admitted responsibility at the scene and police suspected she may have been drinking.
The insurance claim for her personal injury is still going on! My mum has been sent to see two separate doctors to assess her case.
In February, my BF had a smiliar accident – silly bint pulled out etc, but he did not suffer severe injury, just back pain which kept him off work for a few days. Woman did not immediately admit responsiblity and had not been drinking.
He’s already been awarded £1,500!
What I don’t get is why such a cut and dried case like my mum’s is taking so long whilst a case like my BFs (which I thought wouldn’t come to anything) has been sorted already