From the U.S. first written submission in the U.S. - Anti-Dumping Measures on Orange Juice (Brazil) (DS382) dispute (another "zeroing" case):
30. While prior adopted panel and Appellate Body reports create legitimate expectations among WTO Members,18 the Panel in this dispute is not bound to follow the reasoning set forth in any Appellate Body report. A panel is bound to adhere to its own objective assessment as to the interpretation of the covered agreements. The Appellate Body itself has stated that its reports are not binding on panels.19 While the reasoning in such reports may be taken into account, Members are free to explain why any reasoning or findings should not be adopted by a panel bound by Article 11 to make its own objective assessment.20
...
33. The United States recognizes that the panel in US – Zeroing II (EC), while acknowledging the reasoning of previous panels that there is no obligation to provide offsets outside of the context of the weighted-average-to-weighted-average comparison in investigations was “persuasive,” ultimately found that this interpretation was inconsistent with Article 9.3 of the AD Agreement and Article VI:2 of the GATT 1994 solely because it differed from an alternative interpretation developed in Appellate Body reports.25 However, Article IX:2 of the Marrakesh Agreement Establishing the World Trade Organization confers the authority to adopt interpretations of the covered agreements exclusively upon the Ministerial Conference and the General Council.26 Therefore, while the dispute settlement system serves to resolve a particular dispute, and to clarify agreement provisions in the context of doing so, neither panels nor the Appellate Body can adopt authoritative interpretations that are binding with respect to another dispute.
In terms of this specific dispute, it seems unlikely the U.S. argument will have much impact, given what the Appellate Body has said in the Stainless Steel case on the issue of precedent (not to mention what it has said in many cases about zeroing). The Appellate Body was fairly clear on the point (although some nuances of its reasoning may be open to debate). My guess is that the Orange Juice panel will take the Appellate Body's view of precedent and, as a result, follow the zeroing precedents.
But I am interested more generally in the U.S. view on this, as expressed above. I would very much like to see the panel ask the U.S. some questions on this point (although more than likely, the panelists will just ignore it). The U.S. says that such reports "create legitimate expectations," but panels are not bound to follow them. Where would this leave things exactly in terms of the role of prior rulings? How much weight should Appellate Body reports have? It seems to me there is a continuum here, ranging from binding to very persuasive to somewhat persuasive to informative, but I can't figure out exactly where the U.S. thinks Appellate Body reports fall in this continuum.
As a systemic matter (outside the context of zeroing), I'm not sure why the U.S. wants to limit the role of precedent. A more limited role is great if you lose a case as a defendant (e.g., with zeroing), and you get to reargue the law to a future panel; but it's not so great if you win as a complainant, as you may not win the next time. The U.S. wins a good number of the complaints it brings, and it seems to me that the uncertainty of not knowing whether you could win a similar case the next time around would be frustrating.