So what would you do?

[RLC12345678]

I definately think you should tell her, IF she asks. If she asks you when her hubby will be called back for a 2nd interview, I would tell her exactly what happened. If she acts, you should be like..."Oh my gosh! I don't know WHAT his problem is. I gave him advice on how to handle the interview and teh interviewer told me he did the exact opposite! So, unfortunately they aren't calling him back for a 2nd interview."

Then with that being said, let her determine for HERSELF if he is throwing the interviews on purpose. I think you should just be up front and honest about what you know FOR SURE and let her assume what she wants to from it.