You can try to couch things in a more positive manner. Instead of saying, "My program has sh*tty didactics. The attendings don't give a damn about teaching, and we fail our boards." you could try, "I've heard the residents say fantastic things about the formal didactics and the committment of attendings to teaching in the ORs. Your 100% written boards pass rate reflects this. Training in such an environment will facilitate my education and help me become a better anesthesiologist."
That said, I find the truth to be quite refreshing, and someone who has the courage to speak the truth gets extra points from me. However, discretion can sometimes be the better part of valor.