Lawyers for two Perth men who were jailed for life over a fatal shooting only to be acquitted of murder at a second retrial say jurors must follow instructions from judges to ensure a fair process.
Damien Mathews and Hayden Joseph were convicted in April 2013 of fatally shooting 21-year-old Jeremia Iskander in the chest during a fight over a drug debt in December 2011.
The two were sentenced in May 2013 to life behind bars, with a minimum of 14-and-a-half years for Mr Mathews and a 12-and-a-half-year non-parole period for Mr Joseph.
At an appeal, it was revealed that before the jury delivered its verdict, a juror went to a motorcycle racing event and talked about the case to Gypsy Jokers bikies.
Mr Mathews' father and uncle were also bikie members.
The Court of Appeal ruled the juror's conduct "cast a shadow of injustice over the integrity of the jury's verdict" and ordered a retrial.
A second trial started in May but the jury was discharged days later after one juror told the others the men had previously been convicted.
A third trial began that same month and late on Thursday, the two were found not guilty of murder or manslaughter.
Lawyer Vesna Amidzic told AAP on Friday Mr Joseph was feeling relieved with the outcome having spent more than four years in custody.
"There's no real winners in a murder trial," she said.
"It's regrettable that something like this (the retrials) happens when a jury doesn't follow instructions."
Ms Amidzic said the rules were in place to ensure a fair legal process and jurors needed to understand that.
Mr Mathews' lawyer Gary Massey told AAP his client was also relieved with the verdict and agreed jurors needed to follow instructions from judges to ensure a fair trial.
"The temptation to Google something is so easy to do and so difficult to detect," he said.
"Most of the time judges and lawyers won't know about it.
"It was fortunate that this time it did come to our attention."