It's the waste of money that interest me, approximately £330 large spent paying someone to do nothing. That is the nub of it.
Seeing as you mentioned it though, as for the "not guilty" bit, that he was sending saucy and overbearing messages to two young ladies was outside the scope of the BBC investigation because they were not emoloyees - the investigation revolved solely around his alleged behaviour towards BBC staff and whether or not he had broken any in house BBC rules. That is the cold hard fact as regards the Beeb's inquiry.
The messages screenshotted in the media could have been faked by the multiple outlets reporting upon them. Or the could be real. Either way, that wasn't the matter the Beeb looked into. Read the full public statement from the Beeb - very delicately worded.