DMU interviews aren't lax, but they didn't ask off the wall questions, either.
I had good stats, and the areas that were lacking were questioned almost exactly as i expected them to be. I had poor grades for a semester, and they asked very simply and open-endedly, "what happened there?".
the only unexpected question was when I said I play guitar in my free time, and they asked what I would do if it came down to not having enough time to study and play guitar.
I felt comfortable enough with my interview at that point to joke that I would write songs about not having enough time to study, and immediately followed by saying that everything but my family and studying would be secondary, with no exceptions.
The trick to being comfortable in even the roughest interviews is to know above all else that you can succeed at the position, and confidently (but not arrogantly) making that same thing clear to the people interviewing you.