Checklist or not, I'm surprised he got it off the ground without realizing the hydraulics were off. In my experience, raising the collective with hydraulics off is very difficult (heavy). That would be the first indication. He should have also felt it in the cyclic prior to liftoff while he was finding the center point. This just seems fishy to me.... And yes, checklists are very important. I always use them, and I constantly have to remind students to use them. It's rather frustrating when your 50 hour CPL student seems to think he knows it all....