A prosecutor's theory that a teenager killed a neighbour to show his father he was "not a little kid" is "completely crazy" and reminiscent of a Midsomer Murders plot, according to a defence barrister.
Daniel James Sharpe was only 18 when he stabbed Andrew Drake 11 times at Surfside, just north of Batemans Bay, in April 2019.
Now 20 years old, he is on trial in the NSW Supreme Court, denying a murder charge and arguing that he had to kill Mr Drake in order to defend his father David Sharpe against an "ongoing" attack.
The Crown's case, however, is that Mr Drake and David Sharpe were having nothing more than a minor push and shove when Daniel Sharpe intervened, repeatedly "plunging" a knife into the 29-year-old victim.
Crown prosecutor Kate Ratcliffe, in her closing address to a jury in Queanbeyan on Thursday, said Mr Drake did not have any kind of weapon and the younger Sharpe could not possibly have believed it was necessary to do what he did.
She said David Sharpe had "chastised" his son minutes earlier for breaking a glass as he poured drinks for Mr Drake and his sister Penny, who had hopped over the fence to socalise with them.
This "public humiliation", according to Ms Ratcliffe, inspired Daniel Sharpe to jump in when his father began wrestling with Mr Drake.
She said the then-teenager had fatally stabbed Mr Drake, accidentally slashing his father's hand in the process, to prove to his dad that he could fight and that he was "not a little kid".
But on Friday morning, Daniel Sharpe's barrister Troy Anderson told the jury this made no sense.
Mr Anderson said his client did not accept that he had felt humiliated, or that he felt a desire to "impress" his father with violence.
"That's the kind of thing you might see in Midsomer Murders: the son trying to avenge his father," Mr Anderson told the jury.
"It's mad, completely crazy."
Mr Anderson said Daniel Sharpe had only stabbed and killed Mr Drake out of necessity.
He told the jury there was "overwhelming" evidence that Mr Drake had initially been armed with the knife in question, and that it was the 29-year-old who had slashed David Sharpe's hand with it.
Only then, he said, did Daniel Sharpe become involved in the fight, grabbing Mr Drake's arm and twisting the knife into Mr Drake before taking control of the weapon and striking more blows.
Mr Anderson said that even when Mr Drake had been disarmed, he had represented an ongoing threat to the accused and his father.
"The stabbing and killing of the deceased was necessary in the mind of Daniel Sharpe, and his response was reasonable," he said.
Mr Anderson told the jury the simplest explanation for something was usually the right one, and in this case the most obvious reason for his client to kill a man he barely knew was for defensive purposes.
The jury of 11 heard on Friday morning that it would ultimately be left with three options.
These were convicting Daniel Sharpe of murder, alternatively finding him guilty of manslaughter, or clearing him of both.
Mr Anderson said his client should be completely acquitted, or, in the event the jury found the young man's response to a threat posed by Mr Drake unreasonable, "convicted merely of manslaughter".
Ms Ratcliffe, on the other hand, has urged the jury to find Daniel Sharpe guilty of murder, saying the evidence of Mr Drake's sister showed the victim had posed "no threat".
Justice Geoffrey Bellew has begun summing up the case for the jury, which is expected to retire and start deliberating early next week.