The law governing lawyers and public officials is relatively extensive, but I've always thought that even when understood as a matter of legal compliance, keeping out of ethical difficulties does require some moral sensitivity, an ability to feel when something is not quite right and merits further investigation before acting.
The spectacle of Canada's former Prime Minister, the lawyer Brian Mulroney, testifying before a public inquiry the last six days confirms that idea (here) . After he left office Mr. Mulroney met on 3 occasions with Karlheinz Schreiber, a German "businessman" who has subsequently been charged with numerous criminal offences in Germany related to bribery (!), but now spends his time primarily resisting extradition from Canada. On each occasion Mr. Mulroney received $75,000 in cash in an envelope which he proceeded to put in a safety deposit box and/or safe, and did not pay tax on until the payments were going to become public knowledge, at which point he entered into a settlement with the Cdn. equivalent of the IRS. In the course of his testimony Mr. Mulroney attempted to emphasize the legality of his conduct.
Hmmmm. This claim seems dubious at best, on tax grounds alone. And even if it turns out to be correct, surely even the dimmest PR student would be able to spot the issue that taking cash payments in an envelope, in a shady meeting a a hotel, for services not fully defined, is not the best plan, ethically speaking.
As an aside, a point of local pride is that the former Premier of Alberta, Peter Lougheed, also a lawyer, forbade his cabinet from meeting with Mr. Schreiber. Much better moral sensitivity, or personal judgment, I think.