Ewen Macdonald has been acquitted of murder in a court of law but he will still have to overcome the "Bain factor" in the court of public opinion, a top defence lawyer says.

Jonathan Eaton said the best advice he gave clients found not guilty of serious crimes was to accept the allegation would always follow them around.

Mr Eaton had Rex Haig's murder conviction quashed in 2008 and successfully defended George Gwaze on charges of murder and sexual violation in May.

On Tuesday, Macdonald was found not guilty of murdering his brother-in-law and business partner, Scott Guy, in July 2010 after a month-long trial in the High Court at Wellington.

Mr Eaton said that in Macdonald's case – where a crime had clearly been committed and police were not looking for anyone else – there would inevitably be members of the public who thought he was "lucky".

"Regrettably, you're always going to be tainted; whether it's applying for employment positions, starting new relationships, moving to a new town – there's always going to be a Bain factor, which you can't escape."

Mr Eaton said that if Macdonald was to return to Feilding some day, he would have to handle people coming up to him in public and expressing their view about "whether he ought to be out and about". The best advice was not to be provoked into responding, however frustrating that might be.

"My advice to them is ... just remember that moment when you heard the foreperson [of the jury] announce that you're not guilty, and the sense of relief and elation, and don't forget what could have been. If it had gone the other way, it would have been a hell of a lot worse, so from the position you're in, this is not a bad price to have to pay."

Also faced with the question of how to move on is Mr Guy's widow, Kylee, who left the High Court in tears after Macdonald's not guilty verdict was announced, screaming: "He killed my husband."

One person who can sympathise is Hawke's Bay woman Agnes Nicholas, who watched Murray Foreman, then 50, be acquitted of the murder of her husband, Jack Nicholas, 71, after an eight-week trial in 2008.

Mr Nicholas was a farmer like Mr Guy and, in similar circumstances to the Feilding man's murder, was shot dead at the gate of his remote Puketitiri cottage in August 2004.

Mrs Nicholas said she was left in shock and disbelief at the verdict, which she presumed was how Mrs Guy was now feeling.

The fact that a question marks still hangs over her husband's murder bothers her to this day.

- © Fairfax NZ News