Professor Timothy O’Neill opened his Monday Law Bulletin column by asserting that the one law-related idea “that even lay people are aware of” is the erstwhile maxim “Ignorance of the law is no excuse.”He then criticized a recent US Supreme Court opinion that held to the contrary: that a police officer’s reasonable but mistaken view of the law did not justify the suppression of otherwise competent evidence.Professor O’Neill’s column said this ruling left him “scratching …