I have always found when my gut is telling me to back off or take it slower, there is a reason. I may not even be seeing it consciously. The fact that he won't answer questions and changes the subject is concerning for me. I also studied psych in college (no degree yet, associate's in social work). To me, an "innocent" person would want to tell the story and clear their name, in your eyes, not raise more doubt. I also noticed the wording he used, it did seem a little convoluted.