Whilst our engagement with this question no doubt has generalizable implications, it first arose as a result of an experience one of us had when an interpreter terminated their participation in a consultation because the issue of abortion had arisen....
Interpreting is an unusual profession, not least because there is a sense in which the interpreter does not act independently. Insofar as their duties extend to relaying the words of others, they do not engage in any de novo speech acts. Thus, even if an interpreter knows that A is lying to B, it is their professional duty to convey that lie in the same way as it is uttered. Indeed, if that lie is subsequently believed it would be unethical for them to take it upon themselves to point this out. As such, interpreters adopt a morally neutral stance as to the content of the communications they facilitate and with regard to the situations they find themselves.
Contrary to what they suggest, this is a common kind of problem for professionals. Every doctor, every lawyer, every minister, every teacher regularly has situations in which their job is to pass on things with which they do not agree, because it is important for the lines of communication between the client and the system to be clear. But it is also necessary for the professional to be able to judge when they might not be the best way to do this. Emmerich and Phillips argue that Interpreters do not have the right to object conscientiously in these cases. They are assuming in the background the AUSIT Code of Ethics. It's impossible, however, to get the result they want while doing so -- the AUSIT Code of Ethics (rightly) holds up the standard that Interpreters should avoid or should attempt to withdraw from assignments in which their impartiality or detachment might be difficult due to personal beliefs. The idea of Emmerich and Phillips, that because an Interpreter has a duty to convey what is uttered that they therefore have no choice but to accept any assignment and to continue with it regardless of their judgment about whether they are able to remain unbiased and detached in their task, is a non sequitur and absurd on its face -- and there is no way to get from point A to point B here without assuming the conclusion they want. The attempt of Emmerich and Phillips to deny Interpreters a standard right of conscientious objection fails at the starting gate.
It's not essential to the point, and as I say the AUSIT Code of Ethics recognizes a standard according to which Interpreters might engage in conscientious objection if anyone attempts to force them to interpret in a condition that they deem dangerous for their unbiased detachment, but Emmerich and Phillips also show signs that they are overly influenced by an all-too-common superstition about what it is to be a professional:
However, to be a professional is to adopt a particular and socially defined role. To be or act as a professional is, in a sense, to adapt one’s individuality so as to conform with broader, collectively determined, professional responsibilities.
Professional responsibilities are not determined 'collectively'; there is no 'adaptation' of one's individual to the collective. Professional responsibilities are determined individually and refined cooperatively. All professional ethics arises from the actual work of professionals approaching their own work conscientiously; to be part of a profession is not to be part of a 'collective', but is instead to be a worker in a community with other similar workers, sharing what they know and have learned so that the work itself may be done well. The top-down view of professional ethics as descending from 'The Profession' -- I call it the Totalitarian view, because in practice it is used by people trying to deny all sorts of human and professional rights -- is gibberish; professional ethics does not descend from on high, it grows from the soil of actual practice, which is done by individuals and not by collectives. The purpose of codes of ethics put forward by professional organizations is to establish stable reference points of general agreement, to publish what professionals by and large regard as the standards and that people therefore can reasonably expect, not to dictate terms.