I don't think there's any reason to believe the prosecutor is going to tell the BBC the full story behind the decision making for dropping the case, versus a so

I don't think there's any reason to believe the prosecutor is going to tell the BBC the full story behind the decision making for dropping the case, versus a sound bite that seems reasonable. If they had obtained internal first-person memos discussion the reasons for dropping the case, then you could probably assume those would be credible.