Going for affray was a mistake. That requires a bystander to reasonably believe they were in danger. Given that on the video you can see people just getting on with their night and even that a chap was happily stood there filming it that wasn't going to stick.
But then GBH was unlikely to stick when neither side wanted to press charges.
Whole thing was a complete waste of time and money.
The below is quite interesting. I assume as neither party wanted to press charges, the CPS thought they wouldn't get ABH, so went for Affray? -
Assault: intentionally or recklessly placing a person in fear of the immediate application of unlawful force.
Battery: intentional or reckless application of unlawful force to a person.
ABH: an assault (or battery) which results in some injury to the victim that is of more than a trifling nature, e.g. a bruise, a sprain etc. There need be no intention to cause such an injury on the part of the defendant, as long as the offence of assault or battery is made out then if a sufficient injury is the result the defendant is guilty of ABH. So, for example, you raise your fist at someone (an assault) intending not to strike them but they fall over and sprain their wrist. That is now ABH. Of course, charging standards exceed the legal definition and black eyes and bruises are classed only as a battery.
GBH: there are two types of GBH/wounding. The first is a "section 20" which requires and assault/battery with the intention of at least some harm being caused (even minor harm). If the injury caused is serious or is a wound (an injury penetrating the whole skin) then the offence of GBH/wounding is made out. The second type is a "section 18" which requires a serious injury following an assault/battery and an intention to inflict such injury or resist arrest.
Affray: a public order offence in which a person uses or physically threatens unlawful violence towards another. His conduct must be such that an ordinary person of reasonable firmness would be put in fear for their personal safety.
Some examples:
1. You run at someone with a raised fist: assault.
2. You kick someone: battery.
3. You punch someone and break their nose: ABH.
4. You punch someone knowing that you will injure them and they fall over and break their leg: GBH (section 20).
5. You stab someone: Wounding (section 18).
6. You start a fight on a crowded Tube train: affray.