What was wrong with the April Fools joke analysis

I have been asked by some of my students to explain why I think the argument advanced by those who attacked the lawyer involved in the April Fools joke discussion was wrong. If you don't know what this is all about go here and here.

I'll try to keep it brief. The argument advanced by the guy in Ethics Alarms was very simple: lying is bad, thus lying is unethical; the April Fools joke was a lie, thus the lawyer acted unethically. It is a categorical argument, based on a value judgment of the conduct involved. What is wrong with the argument is that legal ethics rules are neither categorical nor consequentialist. That is, they are neither based on any pre-determined value judgment of the attorney's conduct nor dependent on a particular consequence or result. They are contextual. They depend on the circumstances. In some cases, lying is okay (as in lying about wanting to rent an apartment to determine if the landlord is discriminating), while in others it is not (as in lying in court).

In addition, when it comes to conduct outside the practice of law (and under Rule 8.4, which was cited in the debate about the joke in question) courts have always limited their evaluation of a lawyer's conduct to the relationship between the actual conduct and the lawyers ability or capacity to practice law. In some cases, a lawyer's pattern of dishonesty can bring into question his or her trustworthiness to the point where it may be relevant for a disciplinary action while in others it may not.