Insurance Services Office Senior Manager interview questions

A recruiter connected me to ISO in San Francisco. Had a couple of phone interviews and then they asked me to come for onsite interviews. There were the general questions about Statistics, building models and managing teams; there was a presentation as well. I liked most people I talked to -- it seemed a good mix of younger and older workers and the offices appeared sunny and collaborative. I answered all their questions and felt the interview went well in general. The hiring manager in fact told me he hoped I'd join them! However, they came back and said they did not want to move forward because they had earlier thought I was more "senior". I was puzzled -- did they think I had padded my resume or lied about my work experience? Of course I had not. This only leaves the possibility that they expected me to be a bit older. That was the only reason given. I was in my early 30s at that time, had been a manager for 2 years already, and perhaps looked a couple years younger than my true age. This might be a one-off or perhaps the job description had changed in the meantime, but gave an impression of disorganization and lack of professionalism -- though with the economy the way it was in 2009, they could do it.