EY and NYAG case regarding repo 105: From a legal perspective, the question comes down whether EY violated the law as was in effect at that time. From an ethical perspective, the question is whether EY should have been obligated (under business ethics principles and/or professional responsibility standards) to act differently?

In this vein, note the past perfect tense ("should have been") rather than present ("should it"). At the time that these events occured, did EY act ethically?

Even if you believe that it did not, consider this: what should the EY auditors been obligated to do and was it reasonable under the circumstances at that time? Also, you may want to consider what measures EY did have in place that could be easily (and voluntarily) improved to prevent a similar situation from happening in the future