When they made the charging decision they knew she might back out.They’re in a difficult position though. They can only proceed with a prosecution if there’s a realistic chance of conviction. Proving controlling and coercive behaviour under any circumstances is notoriously difficult. Under what we’re assuming these circumstances are, it would be next to zero.
Of course proving C&C Behaviour is hard but that is what they are there for (or should be)
I really am struggling to accept he goes scot free without them at least trying.