How long a sentance wil my boyfriend get?

My boyfriend got into a fight in town last month, he came out of a club to find some drunken girls standing in frton of his car, he asked them poiltley to move from the road so he could p but 1 of them refused, anyway he started the car and touched her wit the bonnet (not to harm her just to scare her, was doin about 1mph)- this girls boyfriend then came over and kicked the wing mirror off his car wich led to the fight, my boyfriend ended up breaking the guys jaw and is now being charged with GBH section 20, he was given bail with curfew untill court on the 14th of this month, he must be in by 8pm but police did a doorstep check at 8:15 and he wasnt in so they arrsted him the next morning and hes now been remanded untill thursday when hes to be sentenced. how long is he likely to get for the GBH and what about the face he broke his bail rules? im really worried, will they take into consideration that the fight was provoked or what?