Every one can fail a checkride at any time. I failed a couple at Riddle myself, and guess what, I learned from them and moved on. Flying in the military for 5.5 years I haven't failed one and I think that is in large part due to the lessons I learned at Riddle.
Showing that you made a mistake and learned from it shows that you are mature, honest, and a professional. Having never made a mistate shows that you are just plain lucky.
Best of luck with the interviews.
Brian