Gordon Flesch Company Field Engineer interview questions

I applied via a contract agency and had a phone interview set up within a week. Phone call was set for a rather early hour of the day with no explanation as to why. Interview was basic review of job history and technical skills all of which made me an ideal candidate for the position. All in all the interview went, at lease in my opinion, very well, so I was a little surprised, when the contract agency said that the company was going with other candidate. When I expressed my surprise my contact at the agency told me that GF is extremely, ridiculously picky about who they hire and that there was no telling what may have knocked me out of the running.