Well, Karina is good, to put it mildly! - She said you just have to practice in order to keep from getting dizzy, or just get used to it. The combination she put together for the non-spotting spins did involve turns that went down the floor, though, and were not in place.
I have to go with one of the other poster's statements, to me a turn can involve rotations using one or two feet. A spin is a rotation or rotations on one foot/leg. And I dare say, in normal circumstances you should spot both types.
Not wanting to put words into Karina's mouth (I wouldn't dare), I thought I might just mention that one of the turns that Karina is fond of doing is a turn where she tilts her head - I think - back and sideways while rotating. And I would guess that turn would be "unspottable" because of the position of the head. So yes there are some instances that you do not spot a turn, but in general I normally spot my turns/spins.
Don't know if this is the type of turn that was being demonstrated in the combination?