Is honest truth a redundancy

At face value it seems to be, doesn't it? But you can lie with half truths, and even with full truths that are carefully selected or taken out of context. The oracles of Delphi never lied, and still drove ignorant men to perdition with a depth of deceit that is breathtaking. So the phrase from US jurisprudence: the truth, the whole truth and nothing but the truth takes on a new meaning.