No a statement will not be a change to his circumstances regarding bail!
We have established the reason for the refusal of bail is that he has a history of assault and the CPS think that if released he will be likely to assault someone again.
One point that I have been wondering about since this question started.
If as you say, your BF was knocked unconscious and can not remember what happened and you were not present when the incident occurred, how do you know he was attacked first? You actually state in your initial question
''So what I heard there was an argument not sure who started it''
You then go on to say ''he does not know who did it''
When this goes to court, what evidence is he intending to present to say he was attacked first? The attacker is hardly going to admit it and you say your BF can not remember what happened.
You have been in a court, you must realise that this ''can't remember/ not sure who hit me'' is just not going to convince anyone.
I am NOT trying to upset you or insult you only to help.
But from what you have told us on here you have very little defence. Your BF admits hitting the other man so hard he split his mouth wide open. His defence will be that it was 'self defence' but you are going to need some evidence of that !
Sorry but saying he woke up and found someone on top of him attacking him is not good enough. You need to explain what happened to get him on the floor. The other side are going to say '' he started the fight and I had to knock him to the ground in self defence, then he attacked me again and split my mouth open''
What happened with the meeting with his solicitor you told us was having ?
That is vital information that we need to give any more advise.