Not if the police attended and witnessed the assault for themselves, we don't know, but the CPS wouldn't be proceeding if they didn't think there was enough evidence.
True...Though they've cocked up before on a few occasions. Maybe Mrs B will do time for contempt of court, and Mr B, walks away scot free!
If necessary a victim can be ruled to attend and give evidence by the court .. known as a hostile witness, rarely happens these days but its usually used to clear up any ambiguity. With the body cam footage recorded from the officers on scene (I presume they were wearing them) they will have recorded injury and initial complaints.
As they're very selective on which cases they dare proceed with, they have been known to chuck a few in fully expecting to lose, especially high profile ones, or it would show that selectiveness for what it is.