What is something I said?

After 33 years of experience creating, editing, critiquing and presenting business documents using Excel, PowerPoint, and Word -- pitching billion dollar asset acquisitions -- I 'did not qualify' for Business Document Expert (Excel, PowerPoint, Word). My interview immediately went in to Review. Was something falsely detected? During the interview I looked straight ahead, spoke naturally, and gave no sign of cheating (because I was not cheating). I completed the assignment with 8 or so minutes left. Was that the issue? Too quick? I know sometimes the chemistry just isn't right, but there are 100 openings. It's not like the competitive intensity of 1 or 2 openings. Can I get some constructive feedback, please?