Having recently watched the second season, I've observed Cain to be officious, cold, and distant versus others. This is particularly visible in her conflict with Commander Adama, and her determination to hit and hurt the Cylons.
Yet, the Razor miniseries shows her differently. There are moments of smiles and levity - she chews out Shaw for late arrival, then comments on having had a "little mid-afternoon snack". Then, of course, the Cylons attacked, and Cain had to protect her ship and crew.
Given two differing view of Cain, I have to wonder if she was always a hardass, but not visibly so during Razor, or did the Cylon attack and aftermath have a lasting effect on her personality?