From New Scientist:
It’s not the first time that people have claimed the discovery of potentially organic carbon in Hadean zircons – but the carbon in those earlier claims turned out to be an artefact of the preparation techniques used to study the zircons, says Harrison. “I think there will be little dispute regarding the primary nature of the inclusions,” he says.
Ultimately, carbon isotope data on its own is too ambiguous to decide whether Hadean carbon is evidence of Hadean life, says Thomas McCollom at the University of Colorado, Boulder. “I know a lot of people want to use such data as evidence of life, but this is governed more by what they want the outcome to be rather than scientific principles,” he says. More.
If they really “want” a very early origin of life, then they don’t want a Darwinian approach. Is this ever discussed seriously?
See also: Life started soon after the planet cooled?
With Enceladus the toast of the solar system, here’s a wrap-up of the origin-of-life problem