In a Program Committee (PC), can PC members non assigned to a paper still have a look at it and make comments influencing the decision, assuming that the reviewing system allow them to access the papers and the reviews?
If they only make a comment, should this comment be sent to the authors (EasyChair, for instance, does not forward the comments to authors)? For instance, consider the case where a PC member thinks that an important reference is missing, regardless of the overall quality of the paper, what should she/he do? Add a comment? Ask to be assigned as a reviewer?