In court today, the accused's wife Anna Macdonald, Mr Guy's sister, sat in the public gallery beside parents Bryan and Jo Guy and older sister Nikki.
On the opposite side of the public gallery, Macdonald's father Kerry sat behind the dock.
Mr King told the jury that Mr Guy's family should not have to be sitting in the courtroom today.
"What happened to Scott Guy was an absolute tragedy. He did not deserve it.''
But he told the jury to put aside the natural desire to resolve the mystery of who killed him.
"One day hopefully it will be, but it's not today.''
Mr King said every strand of the Crown's case failed when the cold, hard evidence was looked at objectively.
"And if it doesn't fit, members of the jury, you know the rest.''
Mr King began his closing address yesterday by saying the case was not about allegations, but about evidence.
He said evidence on the timing of Mr Guy's death, the number of shots fired, a mystery car seen about the time of the murder, and other aspects of the police investigation had raised enough reasonable doubt.
Mr King today said whatever Macdonald thought about Scott and wife Kylee Guy, he would not inflict the the enduring legacy on his family of forever looking over their shoulders and not knowing who the killer was.
The Crown alleges Macdonald put "poisonous notes'' in the Guys' mailbox, burned down an old house on their property and vandalised a new house being built there to intimidate them off the family farm.
Mr King said evidence about the notes was convoluted "rubbish'' and Kylee Guy had never heard of them.
Macdonald regretted the arson and vandalism was making steps to move on from his "appalling'' behaviour.
He did not admit those acts until later because if he had, he would have "lost everything'' - including his family.
Mr King said the reality was Macdonald and Mr Guy had been getting on better than they had in years and were positive about the future.
Proposals to grow the family farming business had not caused a rift between the men, as the Crown alleges.
''To try and twist that into he was murderously worried, murderously insecure ... is totally contrary to the evidence.''
Mr King said it was foolish of Macdonald to lie to police about the arson and vandalism.
But it was not demonstrative of guilt and in every other respect, his evidence could not be discounted or disproved.
On the morning of the murder and throughout the day, Macdonald had acted perfectly normally. He got on with the farm work and was grieving and comforting his wife when he could.
The Crown alleges Macdonald knew Guy had been shot before anyone else, but Mr King said that was not even fiction, but fantasy.
Mr King said evidence about dive boot impressions at the scene had been "fudged'' by forensic scientist David Neale.
The Crown alleges Macdonald wore size nine Proline dive boots with a distinctive wavy pattern when he murdered Mr Guy.
But Mr King said the number of rows of waves on the impressions did not match size nine Proline boots, and if they were of that brand, they were more likely size 12.
Mr King said everything seemed sinister if it was looked at though the "myopic lens of the presumption of guilt''.
He used farm worker Simon Asplin as an example - stressing that he was not accusing Mr Asplin of murder.
Mr Asplin wore size 12 boots, owned a semi-automatic shotgun, knew he had his house to himself on the day of the murder, and had plenty of time to dispose of evidence.
Mr King said he had "deep-seated resentment'' for Mr Guy and had tried to drive a wedge between him and Macdonald.
Mr Asplin snapped at another farm worker when asked who would kill Mr Guy, and on the day before Mr Guy's funeral said: "Well, he's pissed a lot of people off.''
Mr King said there may be perfectly innocent explanations - but very sinister interpretations could be placed on perfectly innocent action.
"When you take your man and you put him in that dock, things can be made to seem to fit.''