'Unproven allegations'
All allegations are unproven, that's what an allegation is.
If you are saying it is your view that the BBC should not publish any reports based on an allegation then, that your view, fair enough. There wouldn't be much news about though.
For the record I'm not taking the side of CB here. I've seen her interviewed a couple of times and have found her evasive and er ... unconvincing if you know what I mean (cue posts telling me what wonderful things she's has done), I just don't think this is a biased news report.