Dead case walking:
Propensity evidence is an argument as to something a person is likely to do, mainly because he or she are said to have done so before, spoken about, or displayed the character to do so. When a case has no evidence, the Crown, if pig-headed and intent of prosecuting, might embark on seeking from the Court to admit propensity evidence. That's what happened in Scott Watson's case. There were no violence convictions of prior offending for police use. So they invented some. They did that in various ways but all to the same point - that the jury, if they had any doubts about Watson's guilt, could reflect on things he allegedly did or said to a number of people - who it is now clear could be leaned on, or given 'favours,' or because overall Scott was a bastard wanted for an unsolved alleged murder on Great Barrier Island, who had to be stopped.
Somehow the Judge allowed that evidence, after first ruling it as too dangerous to be admissible. Evidence, which when the Judge 'changed his mind' could have made the Jury feel that Scott was the likely killer because of that material which in totality was not actual evidence but rather allegations that were never proven, 'statements' for which there is no material proof had ever been said and which were not revealed by witnesses at first call. The totality of such, never proven as true or beyond reasonable doubt testimony, would have been unsettling to the juror's minds particularly for those with a belief that police are always right. Scott Watson was being 'tried' for things that could not be proven true but which the Crown was allowed to use to prove a case for which they had minimal, really no evidence. It's a lot to think about in a tight situation, taking objective focus away from the reality that there was no proof of Ben and Olivia ever going aboard the Watson boat or even being in his company. There's remains a strong (and hidden until now) argument about which boat the couple boarded despite a parcel of strong evidence put together over 2 decades - in reality the 'propensity evidence' is a fragile connection between alleged random events linked by alleged talk regarding alleged evidence for which there is no confirmation.
The Crown didn't have proof of death, the Crown didn't have Watson and the couple at any point together, also the further weakness of his being dropped off to his boat alone at the end of a long night with sunrise less than hours away. Nothing found on Watson's boat provided any proof of the couple being there other than speculation. So the argument for propensity evidence also relied on a lack of physical evidence critical to its integrity. That is the pattern of the evidence in this case - a lack of evidence and unsubstantiated talk to fill gaps. Boats shrunk and grew in size, changed colour and number of masts. Sequences of events alleged by the Crown were not linked together, the investigation was not thorough because a target had already been identified from which point all other leads were ignored. Not one question raised from either the Tam team, Police Headquarters or indeed the Crown - no one willing to 'say we never properly investigated this case - we fixed on one potential suspect and completely ignored the rest.' That investigative conduct was somehow permissible, as it is now. That will change in whatever way Scott's current Royal Prerogative of Mercy appeal is settled because a question for the reviewer, and this Government, is whether lack of evidence in continuity is actually evidence at all. Time is going to show that it is not, and this case against Scott Watson will fall in the disgusting heap it has always been.