It goes without telling (so I'll tell it here), you should be honest with your accountant, lawyer, and doctor. Why do I bring this up? Because I inherited a new client with an IRS audit issue and she lied through her teeth to me.
My job is too help you. What you tell me is confidential. If you lie to me I can't help you. You are also wasting my time and your money. For your sake, and my sanity, be forthright with me. I don't blab to the IRS. I help you formulate a plan to manage your tax situation/audit.
The lie didn't cause additional problems, however, I will no longer work with this client. When I make a client's life easier, I am tickled to death; when jerked around, I pare down the client list by one. You paid for a professional to serve your needs, treat me like said professional.
Ok, the rant is over.