I hate the fact there's this "sue" mentality. You can't by law be honest about why you didn't hire someone for fear you can be taken to court. Yes, by all means there should be an explanation!
I only applied for one job here (no interview, sent in my CV) and it was so apparent by the rejection letter I got that they so didn't even read my CV, it was untrue. Oh man, if they only knew what they passed up! I had so much experience, won design awards up the wazoo and I am such a dedicated worker...plus I'd have done the job for peanuts. I'd love to know what their reason was! I'm suspecting it was age.
Oh, about the CV...a friend of mine at the time I did mine actually wrote and advized on writing CVs as a profession...and gave me a lot of pointers; said it was the best he'd seen. This weren't no ordinary CV.