When I spoke to them they said if they had an AI that could do as good a job as people, they wouldn't need contractors. I think Google's approach would be to contract a bunch of scientists, have them read and interpret the papers, then use that data to train a deep net that could do it more accurately (you need some baseline humans to act as golden standards). This worked well for Google in several publicized examples, such as discriminating house numbers from numbers on cards in Street View imagery.