Someone asked me why employers would want recruiters to prepare candidates for interviews. "Isn't that like cheating? Wouldn't they get a better vantage point to see how people really are if they don't know what to expect in the interview?"
In fact, I actually had a new client unexpectedly call my candidate BEFORE the scheduled appointment so he wouldn't be "prepared" and so he could see a "real picture" of this candidate. The candidate did okay because he was very senior level and had the experience this client needed, but he certainly could have done significantly better if he were prepared. The employer and I had a good discussion about it afterwards, and I thought if there were other employers who share this opinion that they might be interested in the topic as well.