I disagree somewhat
Life tends to create molecules that are hard to explain via abiotic processes... if simple molecules are found that are hard to explain by abiotic means that isn't proof, since we really don't know the conditions down at the seafloor perhaps 100s of miles below... what temperatures, pressures, material, and catalysts are present... but if we find really complicated protein like molecules, perhaps complex molecules all with the same chirality then that becomes something approaching hard proof...