Underwriting in the box

I have been an underwriter for many years.  Through my experience on the "If it is in the Box" type loans, this becomes very scary.  I had a couple occasions when I was questioned on a couple conditions that I had added to a loan approval, it became an altercation with the processor and loan officer.  My supervisor then asked why I had added that condition, due to what was in the file, I felt it necessary.  Because of the condition, we found that it was a fraud loan.  There are just some things that don't feel right in some files.  We underwriters don't like to be detectives, but we don't want the loan to go bad and come back to repurchase the file.  This happens more than what you think.  Not only do we have to repurchase the file, it also goes against the underwriter.  Any comments on this would be greatly appreciated.