SAIC interview questions

Recruiter contacted me to set up a phone interview with the hiring manager. Hiring manager interviewed me over the phone and talked about the nature of SAIC's organization and the position at hand. She asked about my previous work experience and how it relates to the position.

The hiring manager forwarded my resume to the hr. And the hr called me up on a Friday morning. She asked several basic questions about my working permits, my relevant education background. Two behavioral questions but no technical questions at all. A follow up phone call from hiring manager was on next Tuesday (quite efficient by the way). We didn't chat a lot before we get to the interview. He asked me to describe relevant experience I listed on my resume and particularly asked me what my role was in those task. Overall it's a nice experience, but I don't know why I didn't get an offer.