A friend of mine recently interviewed at my workplace, and was shown around town ( we don't currently live in the same city) by myself and a few co-workers. After a week of not hearing any news from her whether she was hired or not, I decided to privately ask my manager, who conducted part of her interview, what her status was. He said that it was unlikely that she would be hired, and gave me the reason, which I won't share publicly. Another week later, and my friend got back to me saying that she got the official "thanks but no thanks" letter.
My question: should I tell my friend the reason why she was not hired, in order to help her with any future interviews that she will have?