In 1980, 1985 and 1989, ministers' advisers on the Law Commission - which puts forward proposals for modernising the legal system - and the Criminal Law Revision Committee called for jurors to have the power to find a murder suspect guilty of the lesser crime of manslaughter if they think he has taken his right of self-defence too far.
Each time the proposal has been made, the Lord Chancellor and Home Secretary have decided to do nothing. The law has remained that if the jury thinks a deliberate killing could be a 'reasonable' and 'necessary' act of self-defence, it must acquit.
Mr Elliott, 19, was freed in a case that shocked the country after his lawyers argued that he had been defending himself when he stabbed Mr Osborne, a 40- year-old music teacher, in the heart during a confrontation on a south London housing estate.
The teenager, who had a string of convictions and emerged unscathed from the encounter, claimed he had not wanted a fight and was just pushing his penknife forward to stop Mr Osborne attacking him with a hammer.
Mr Justice Kay told the jury: 'A killing in lawful self-defence is no offence at all.' It was up to the prosecution to prove that Mr Elliott had not instinctively defended himself.
After the verdict senior lawyers said that juries were being put in impossible positions. Nicholas Purnell QC, a former chairman of the Criminal Bar, said: 'Juries agonise. It's very difficult to decide what's necessary and reasonable self-defence. They often come down on the defendant's side because all the law allows them to do is make an all-or- nothing decision: life for murder or acquittal.
'I'm sure that the public would like to have the leeway to say that a man was defending himself - and so should not be found guilty of murder - but add that he had gone too far and should be convicted of manslaughter.'
Andrew Ashworth, professor of law at King's College London and a member of the Criminal Law Revision Committee, said he suspected that political fears that the pro-hanging lobby would take over the debate had stopped Bills going to Parliament to sort out the 'mishmash' of legislation governing violent crimes.
It remains to be seen if Michael Howard, the Home Secretary, who has called for the papers on the Elliott case, will now act. The constraints on judge and jury make the wild headlines of a 'perverse verdict' and 'justice lying bleeding' which filled the press last week seem wilder still. There were claims that the jury was not told about Mr Elliott's criminal record: he is a disturbed and nasty piece of work who had been in the Aycliffe Centre, Co Durham, which houses some of the worst young offenders in the country, and has convictions for burglary, bag-snatching and car theft.
But the jury did know most of this. The defence revealed Mr Elliott's record to support its point that he had never been involved in violence.
There were allegations that Mr Justice Kay failed to direct the jury properly. But his painstaking summing-up, which covers 45 pages of closely typed A4 paper, shows this was a very difficult case which no jury would find easy.
Mr Elliott and a friend had been drinking lager and taking LSD on 10 December 1992. They were wandering the streets and Mr Elliott was stabbing his penknife into car tyres. Diane Osborne - whose own car had been vandalised twice - saw the two and followed them. 'You are the ones who have been doing the cars around here,' she shouted when they spotted her. 'You little bastards. I'm going to call the police.' They called her a 'dickhead' and told her to 'fuck off'.
Mrs Osborne went home and told her husband. He said it was pointless calling the police - they had been called before but never showed up - and went upstairs to fetch his hammer. The judge said the jury had to decide if he intended to use it.
Husband and wife set off together across the estate. According to one witness, Mr Osborne said: 'If I catch the bastards, I'll knock their heads off.' The teenagers ran into a block of flats where Mr Elliott's girlfriend lived. According to her mother, they were frightened. She did not let them in.
Mr Osborne spotted Mr Elliott on a balcony and called to him. His wife claimed the teenager replied: 'If you want me, fucking come up here.' Mr Elliott denied issuing a challenge: if he had, he could not later have claimed he was defending himself. He said he was frightened and tried again to get into the flat. 'Let me in,' he said he shouted to his girlfriend's mother. 'The geezer's gonna hurt me, he's got a big club hammer.'
The mother half confirmed this. She said she heard Mr Elliott cry: 'For God's sake open the door. Let me in. Let me in.'
Mr Osborne went up the stairs at a slow run. The next thing his wife knew, she said, was that Mr Elliott was on the stairs shouting: 'I've done him, I've done him. I'm gonna do you.' Her husband came down and collapsed.
Mr Elliott followed, 'elated', and kicked Mr Osborne time and time again, she said. He punched her when she grabbed him and tried to make him stop, she said, and let loose a stream of obscenities.
Mr Elliott denied all of this. He said he was trapped, got out his knife because Mr Osborne 'had the hammer full stretch and was going to hit me' and stabbed him in a panic.
After the fatal blow, he said he had gone down the steps and merely pushed Mrs Osborne off when she seized him. He denied kicking Mr Osborne or crying 'I've done him.'
No one apart from the teenager witnessed the stabbing, so the prosecution had to prove he was a liar to undermine his account of the confrontation.
But testimony from a pathologist on whether the teenager was lying when he said he did not kick the dying man was hotly argued. Both sides claimed it supported their version of events.
After four and a half hours of deliberation, the jury cleared Mr Elliott. He left the Old Bailey showing no remorse. 'The bloody court finally did something right,' he said.
Most people would think that Mr Elliott has no redeeming qualities. But that does not mean that, with homicide law in its present state, the jury was wrong. Mrs Osborne now has to cope with the killer of her husband living a few streets away. 'We're not moving, we've done nothing wrong,' she said. 'Everyone around here is worried now he's back. He's done the ultimate - he's killed and got away with it.'