Who is at faul

i had an accident last night where a car drove into the back rear side of my car.

To paint the picture i was reversing out of my driveway onto a main road, further down the road there is a bend and there was no oncoming traffic when i reversed out.  I reversed fully out onto the road and was stationary and about to drive off then i see this car coming towards my side and slams into my car.  I then get out the car to speaqk to the driver and then one of the passengers who was built like a muscle man comes out and trries to shove me back into my car and f*** o** almost as if to get me to drive off so they could get out of there. fortunatley i was going nowehere as i was right outside of my house.  Luckily my mother heard all this raucus and stop this guy beating me within in a inch of my life which he was threatening to do.  The situation was difused and myself and the driver exchanged details.  The driver actually said and i quote "i braked too late", which in my eyes is admitting liabilty.  Given the fact i was stationary in the middle of the road, about to drive off when he hit me.  I have checked on police websites and reversing off my drive is not illegal.  Is this their fault?  Would greatly appreciate the advice folks.  thankyou