You might find Sissela Bok's books, Lying: Moral Choice in Public and Private Life and Secrets, interesting. Boiled down, her arguments amount to 1) there is rarely adequate justification for lying, and 2) the problem of secrets is far more complex. The arguments are very good and well-supported.
If it was worth taking seriously it also would have been much longer. Go read Sissela Bok's Lying: Moral choice in Public and Private Life then try taking Harris seriously.
If you are seriously interested in the ethics of lying, I recommend Sissela Bok's Lying: Moral Choice in Public and Private Life. It is one of the few books I gave 5 stars to on Amazon.