Photographer won't give references to call--sketchy or normal?

We interviewed a photographer whose work we love on Saturday. The interview went pretty well, but I was put off by his response when I asked for references of people I could call or email. He said that he wouldn't feel comfortable with giving out people's information, and that he could give me websites that have reviews of him...now of course I checked all of them....and they're all fabulous, but I just think it's too easy to fake those kinds of things. Am I being too cautious or should this be a major red flag? My fiance didn't seem to think it was weird.