Expert witnesses have hailed a judge's ruling that paediatrician Professor Sir Roy Meadow should not have been struck off for giving flawed evidence.
Prof Meadow said he was 'relieved' at the decision
Dr Harvey Marcovitch, who gives expert testimony, said the High Court decision was an "exciting" change in the law.
Prof Meadow gave flawed evidence on sudden infant death at Sally Clark's 1999 trial for the murder of her sons.
Mr Justice Collins said professional bodies should not punish experts over evidence given in good faith.
Dr Marcovitch, also a paediatrician, said the judge had effectively changed the law to give expert witnesses more protection.
"What he's said is that if you give expert evidence in court you are protected.
"What you say is privileged to the extent that your registration body can't take action against you if what you say turns out in the end to be wrong."
He added that experts would not be allowed to lie under oath or give "ludicrous" evidence.
'Lack of expertise'
As well as ruling Prof Meadow should not have been struck off, Judge Collins also overturned the General Medical Council's decision to find him guilty of serious professional misconduct.
Sally Clark: Served three years after being wrongly convicted of killing her two sons
Angela Cannings: Served 18 months after being wrongly convicted of killing her two sons
Donna Anthony: Served six years after being wrongly convicted of killing her son and daughter
Trupti Patel: Acquitted of killing three of her children
He said Professor Meadow had misunderstood and misinterpreted the statistics by claiming the probability of two natural cot deaths occurring in one family was 73 million to one.
"It was a mistake ... that was easily and widely made.
"It may be proper to have criticised him for not disclosing his lack of expertise, but that does not justify a finding of serious professional misconduct."
Sally Clark was sentenced to life in prison for murder but had her conviction quashed.
Professor Meadow's figure on the likelihood of cot deaths was disputed by other experts who argued genetic and environmental factors made the odds of a second cot death in the same family closer to 200 to one.
The paediatrician also testified at the trials of Angela Cannings and Donna Anthony, both freed on appeal after being convicted of murdering their children.
Mrs Cannings said she was "disappointed and disheartened" by Judge Collins' ruling, while a Clark family solicitor said professional bodies had been "neutered".