Yes, they found a statistically significant increased risk, but the risk was lower (roughly half) than driving at .08, which suggests that it should not be illegal. Also, if you read the actual article including the discussion at the end they discuss why they think their combined risk is an overestimate. In fact the main reason I linked to that study is because of their arguments in the discussion, which are not only critical to understanding the paper at hand, but also for understanding the quality of the findings of other similar studies.