In some publications (mostly CS conferences), there are associate chairs or 'meta-reviewers' whose sole job is to manage the peer review for a paper. They will

In some publications (mostly CS conferences), there are associate chairs or 'meta-reviewers' whose sole job is to manage the peer review for a paper. They will read the reviews and if there isn't consensus, they'll ask the reviewers to read the other reviews and have a discussion. It is usually 3 reviewers and 1 meta-reviewer per paper, so there are often 2-1 splits. The meta-reviewer doesn't just send the reviews to the authors with no commentary. They write a summary of the reviews with a recommendation about what to do next. If there are contradictions and no consensus is reached, it is their job to decide which concerns the authors need to respond to in order to get it published. They aren't bound by the reviews, they can disregard one if they feel like it is unfair, although sometimes the rules say they must get another reviewer to write a 4th review.